Now a battery made out of wood!.

In an era where it is cool to be environmentally aware, scientists at the University of Maryland have come up with a formula for batteries that can be counted as cool. These batteries have wood as a major element in their formation, besides fiber and sodium, making them sodium powered batteries. Sodium-ion batteries are, incidentally considered less powerful and efficient than their lithium-ion counterparts. That doesn’t however mean that these batteries can’t be useful.

According to the team of these scientists, these wooden batteries might not end up within your smartphone or your laptop or in any other fancy gadget, but they are extremely useful for storing power on a large scale basis, given the fact that they are good for storing electrolytes as they can swell and contract many times over.

The side effect of the process, which will lead to erosion in battery capacity is the fact that the wood wrinkles due to the stress involved, but this doesn’t stop the battery from working, In fact, according to the claims of these scientists, the batteries can be charged and recharged over 400 cycles and have a capacity of 339 mAh/g. This will only increase as the scientists better the design.

Large scale production, however, is still some way off as what has been revealed is a working prototype at best. The discovery, however, does bode well for the future given the fact that, this is, in essence a low cost, environmentally friendly battery tech.

“The inspiration behind the idea comes from the trees. Wood fibers that make up a tree once held mineral-rich water, and so are ideal for storing liquid electrolytes, making them not only the base but an active part of the battery,” says Hu, an assistant professor of materials science, at the University.

E-waste Management In India

E-waste Management In India.

You are welcome to change your personal computer, cell phone, refrigerator, or for that matter any electronic or electrical gadget, but be careful while disposing of the old one. Throwing it into the dustbin is not the proper disposal of an electronic equipment which has attained obsolescence as per your judgement. 

It may end up adding to e-waste, which creates problems for the ecology in general and directly or indirectly for the living beings around there through air, water and soil pollution.

The aim of this article is to spread awareness among our readers about the various issues involved in generation and management of e-waste, particularly from Indian perspective.
What is e-waste?
Electronic waste (e-waste) comprises waste electronics/electrical goods that are not fit for their originally intended use or have reached their end of life. This may include items such as computers, servers, mainframes, monitors, CDs, printers, scanners, copiers, calculators, fax machines, battery cells, cellular phones, transceivers, TVs, medical apparatus and electronic components besides white goods such as refrigerators and air-conditioners.

E-waste contains valuable materials such as copper, silver, gold and platinum which could be processed for their recovery.

Is e-waste hazardous?
E-waste is not hazardous per se. However, the hazardous constituents present in the e-waste render it hazardous when such wastes are dismantled and processed, since it is only at this stage that they pose hazard to health and environment.

Electronics and electrical equipment seem efficient and environmentally-friendly, but there are hidden dangers associated with them once these become e-waste. The harmful materials contained

 in electronics products, coupled with the fast rate at which we’re replacing outdated units, pose a real danger to human health if electronics products are not properly processed prior to disposal. Electronics products like computers and cellphones contain a lot of different toxins. For example, cathode ray tubes (CRTs) of computer monitors contain heavy metals such as lead, barium and cadmium, which can be very harmful to health if they enter the water system. These materials can cause damage to the human nervous and respiratory systems. Flame-retardant plastics, used in electronics casings, release particles that can damage human endocrine functions. These are the types of things that can happen when unprocessed e-waste is put directly in landfill.

The scenario
The Basel Action Network (BAN) which works for prevention of globalisation of toxic chemicals has stated in a report that 50 to 80 per cent of e-waste collected by the US is exported to India, China, Pakistan, Taiwan and a number of African countries. This is done be-cause cheaper labour is available for recycling in these countries. And in the US, export of e-waste is legal.
e-waste recycling and disposal in China, India and Pakistan are highly polluting. Of late, China has banned import of e-waste. Export of e-waste by the US is seen as lack of responsibility on the part of Federal Government, electronics industry, consumers, recyclers and local governments towards viable and sustainable options for disposal of e-waste.

In India, recycling of e-waste is almost entirely left to the informal sector, which does not have adequate means to handle either the increasing quantities or certain processes, leading to intolerable risk for human health and the environment.

Dynamics of e-waste generation
Telecommunications and information technology are the fastest growing industries today not only in India but world over. Manufacturers’ Association for Information Technology (MAIT) has collected the following statistics on the growth of electronics and IT equipment in India:
1. PC sales were over 7.3 million units during 2007-08, growing by 16 per cent. There is an installed base of over 25 million units.
2. The consumer electronics market is growing at the rate of 13-15 per cent annually. It has an installed base of 120 million TVs.
3. The cellular subscriber base was up by 96.86 per cent during 2007-08. Its installed base is estimated to cross 300 million mark by 2010.

With the unprecedented induction and growth in the electronics industry, obsolescence rate has also increased. People are phasing out/replacing their IT, communication and consumer electronics equipment including white and brown goods as shown in Table II.

As per a GTZ-MAIT sponsored study conducted recently by IMRB, e-waste generated in India during 2007 was around 332,979 MT besides about 50,000 MT entering the country by way of imports. The reasons for generation of this large quantity of e-waste were unprecedented growth of the IT industry during the last decade, and the early product obsolescence due to continuous innovation. Thus the net effect is the e-waste turning into a fastest growing waste stream.

However, the total e-waste avail-able in 2007 for recycling and re-furbishing was 144,143 MT. Of this, only 19,000 MT of e-waste could be processed.

Components of e-waste management
The major components of e-waste management are:
1. e-waste collection, sorting and transportation
2. e-waste recycling; it involves dismantling, recovery of valuable resource, sale of dismantled parts and export of processed waste for precious metal recovery

The stakeholders, i.e., the people who can help in overcoming the challenges posed by e-waste, are:
1. Manufacturers
2. Users
3. Recyclers
4. Policy makers

e-waste concerns and challenges
1. Accurate figures not available for rapidly increasing e-waste volumes—generated domestically and by imports
2. Low level of awareness among manufacturers and consumers of the hazards of incorrect e-waste disposal
3. No accurate estimates of the quantity of e-waste generated and recycled available in India
4. Major portion of e-waste is processed by the informal (unorganised) sector using rudimentary techniques such as acid leaching and open-air burning, which results in severe environmental damage
5. e-waste workers have little or no knowledge of toxins in e-waste and are exposed to health hazards
6. High-risk backyard recycling operations impact vulnerable social groups like women, children and immigrant labourers
7. Inefficient recycling processes result in substantial losses of material value and resources
8. Cherry-picking by recyclers who recover precious metals (gold, platinum, silver, copper, etc) and improperly dispose of the rest, posing environmental hazards
9. No specific legislation for dealing with e-waste at present
Status of e-waste initiatives
The Ministry of Environment & Forests (MoEF) of the government of India is responsible for environmental legislation and its control. The Central Pollution Control Board (CPCB), an autonomous body under the MoEF, plays an important role in drafting guidelines and advising the MoEF on policy matters regarding environmental issues. Historically, in 2001 in cooperation with MoEF, the German Technology Cooperation (GTZ) began work on hazardous waste management in India through the advisory services in environmental management. Subsequently, Swiss Federal Laboratories for Material Testing and Research (EMPA) started to implement its global programme ‘Knowledge Partnerships in e-waste Recycling.’

Combining the knowledge and technical expertise of EMPA on e-waste management, coupled with the field experience of the Indo-German projects in managing hazardous waste in India, the Indo-German-Swiss e-waste initiative was born in 2004. The vision of this initiative is to establish a clean e-waste channel that is a:
1. Convenient collection and disposal system for large and small consumers to return all their e-waste safely
2. Voluntary system for modern and concerned producers to care for their product beyond its useful life
3. Financially secure system that makes environmentally and socially responsible e-waste recycling viable

The objectives of the initiative are:
1. Reduce the risks to the popula-tion and the pollution of the environ-ment resulting from unsafe handling
2. Focus on knowledge transfer to and skills upgrade of all involved stakeholders through trainings and seminars
3. Target mainly the existing informal recyclers allowing for their maximum but safe participation in future e-waste management by facilitating their evolution and integration in formal structures

The milestones achieved so far are:
1. Improved awareness:
• Three WEEE Care! Initiative workshops in Bangalore sup-ported by the Goethe Institute
• National e-waste workshop in Delhi, hosted by MoEF

2. Improved stakeholder engage-ment:
• Formation of the e-waste Agency (EWA) brings together industry, government and NGO to work on a sustainable e-waste management strategy for Bangalore
• First national e-waste workshop held, defined a way forward
• First national workshop on e-waste guidelines held, organised by MoEF

3. Improved estimates of e-waste:
• Rapid assessments in Delhi and Bangalore of the quantities being generated, and identification of the e-waste recycling hot-spots
• National-level desk study to assess e-waste quantities

A national-level assessment of electronics and electrical equipment waste (WEEE) by MoEF/CPCB/IRG/GTZ lists the top ten most polluting states and cities of India as shown in Tables III and IV. The figure are taken from the presentation of Dr Dilip B. Boralkar at National Conference on E-Waste Management, an Indo-German-Swiss E-Waste Initiative, at New Delhi on December 10, 2008.

The MAIT-GTZ study on e-waste found that 94 per cent of the organisations studied did not have any policy on disposal of obsolete IT products. Though many respondents (200 corporates and 400 households) were aware of e-waste, they were lacking in action.

Vinnie Mehta, executive director of the MAIT, in his presentation at National Conference on E-Waste Management (an Indo-German-Swiss E-Waste Initiative), listed the following legislations that cover different aspects of e-waste:
1. The hazardous waste (management and handling) rules, 1998 as amended in 2008 for toxic content—registration mandatory for recyclers
2. Municipal solid waste management and handling rules for non-toxic content
3. Basel convention for regulating trans-boundary movement
4. Foreign trade policy, which restricts import of second-hand computers and does not permit import of e-waste
5. Guidelines by Central Pollution Control Board (2008)

The guidelines notified in April 2008 identify and recognise:
1. Producers’ responsibility
2. RoHS (restriction on hazardous substances)
3. Best practices
4. Insight into technologies for various levels of recycling

Mehta said that the guidelines explicitly mention the need for a separate legislation for implementing producers’ responsibility. He said that e-waste is ‘distinct’ as it is an end-of-consumption waste while hazardous waste results from a distinct industrial process. The Environment Protection Act provides for separate regulations for waste with ‘distinct’ characteristics—Biomedical Wastes (M&H) Rules 1998, Batteries (M&H) Rules 2001, etc.

Advocating a separate legislation for e-waste, he said that in his recent presentation to members of the parliament he has emphasised that e-waste value chain is rather complex as it involves multiple players—producers, distributors, retailers, end consumers, collection system and recyclers—while hazardous waste chain involves only the occupier/generator and the operator. Recovery of non-ferrous metals and reprocessing of used oil are the only two major activities in hazardous waste recycling, while e-waste recycling involves refurbishment for reuse, dismantling and precious metal recovery, which is a complex process.

Structure of the Proposed e-Waste Legislations

1. Title: E-waste (Management & Handling) Rules to be published under the Environment Protection Act 2. Objective: To put in place an effective mechanism to regulate the generation, collection, storage, transportation, import, export, environmentally sound recycling, treatment and disposal of e-waste. This includes refurbishment, collection system and producer’s responsibility, thereby reducing the wastes destined for final disposal. 3. Essence: The producer of electrical and electronic equipment is responsible for the entire life cycle of its own branded product and in particular the environmentally sound end-of-life management and facilitating collection and take back. 4. Responsibility of each element in the e-waste value chain: • Producers • Dealers • Collection agencies/collection Centres • Dismantlers • Recyclers • Consumer and bulk consumers 5. Procedure for authorisation of producers, collection agencies, dismantlers, recyclers and enforcement agencies 6. Procedure for registration/renewal of registration of recyclers 7. Regulations for import of e-waste 8. Liability of producers, collection agencies, transporters, dismantlers and recyclers 9. Information & tracking 10. Elimination of hazardous substances used in e-equipment 11. Setting up of designated authority to ensure transparency, audit and inspect facilities, examine authorisation/registration, etc

e-nam (EWA Newsletter for Awareness and Management) in its September 2008 issue has brought out the latest activities of EWA, MAIT-GTZ and others involved in the e-waste field. It has published extracts of an article titled ‘Progress on e-waste, but Too Slow’ by Mini Josheph Tejaswi. The statements of various experts quoted in the article are reproduced below:

Lakshmi Raghupathy, former director in the ministry of environment and forest and an expert in e-waste management, said that governmental regulations should make the producers solely responsible for the entire life-cycle—from manufacturing to recycling—of their products.

Nitin Gupta, CEO of Attero Recycling, said enterprises should be extremely careful and responsible while throwing their unwanted computers and storage devices.

Computer manufacturers in India are slowly getting active in e-waste management. “We are working with all stakeholders in the e-waste management eco-system,” said S. Shankar, director (manufacturing and supply chain) in HP. The company has initiated a three-pronged strategy: partner with e-waste recyclers, build awareness among individual/enterprise customers and work with NGOs, recyclers, collectors and dismantlers.

Anne Cheong, senior service specialist in Dell, said each manufacturer has an individual producer responsibility. “We start from home. We have proper recycling facility in all countries including India. We are exploring that in Karnataka as well.”

Though companies claim they are taking action, many don’t believe enough is being done. “Things are very slow. Corporates are yet to understand the importance of it,” said Wilma Rodrigues, founder member of Saahas, a development organisation. Decisions related to e-waste management, she said, are still taken by junior employees in organisations, with top executives not even looking at it. Almost every company has some mention on its website on e-waste management, but very few are doing anything. The country has twelve authorised e-waste recyclers including e-Parisara and Ash in Bangalore, Tessam in Chennai and Eco-Reco in Mumbai. Ramky Group is setting up the country’s largest integrated e-waste management facility in Bangalore in collaboration with GTZ, while Attero is building an integrated e-waste recycling plant in Utter Pradesh.

D.C. Sharma, vice president of Ramky Enviro Engineers, cautioned that no player should indulge in cherry-picking, collect whatever one thinks is worth and leave the hazardous portions out. Ramky is also building a transfer storage disposal facility (landfill) for hazardous waste at Dobbespet on Tumkur Road.

Finally, through improved e-waste management in the major Indian cities, the e-waste initiatives taken in the country will achieve better environ-mental conditions. Moreover, health conditions of workers active in the e-waste recycling sector will enormously improve at the local level. As an overall effect, the living conditions for the neighbouring population will be better. The already existing schemes of e-waste recycling and material recovery, mainly in the informal sector, will be transformed to transparent and workers- and environment-friendly methods. In the long term, the problem of improper e-waste recycling will disappear due to improved methods, implementation of a take-back system and consideration of the extended producer’s responsibility.

Experience exchange on national and international levels, including know-how transfer, is being facilitated through the various initiatives. Thus, a dialogue platform for Indian and European e-waste experts has been created, opening the doors for future industries to be developed and cooperation activities to be per-formed for technology and knowledge transfer.

Microwave Tubes Making a Comeback

Microwave Tubes Making a Comeback.

Scientists are looking back at the microwave tubes for high-power and high-frequency applications because only these can handle a power of up to 300 megawatts at a frequency of 1 Ghz.

A high-power microwave system consisting of a high-power microwave tube, high-voltage measurement chamber and power conditioning unit

In 1904, J.A. Fleming introduced the vacuum tube diode. After the second world war, electron tubes were used to develop the first generation of computers but these computers were impractical due to the  large sizes of the electronic components. In 1947, John Bardeen, Walter Brattain and William Shockley demonstrated the amplifying action of the firsttransistor at Bell Telephone Laboratories. They received a Nobel Prize for it. 

Bipolar transistors and digital integrated circuits (ICs) were made fist. Analogue ICs, large-scale integration (LSI) and very-large-scale integration (VLSI) followed by the mid-1970s. A VLSI design consists of thousands of circuits on a single chip with transistors acting as on/off switches or gates between them. Transistors are good for low-power and low-frequency applications. Microcomputers, medical equipment, video cameras and communication satellites are all examples of devices made possible by using ICs. 

From the day of invention of vacuum tube till today, when millions of transistors are fabricated on a single chip, technology has advanced a lot. But scientists are looking back at the microwave tubes for high-power and high-frequency applications because only these can handle high power (nearly 300 megawatts) at high frequency (nearly 1 GHz). 

The term ‘microwave’ denotes the techniques and concepts used as well as a range of frequencies. Microwaves travel in matter in the same manner as light waves. These are reflected by metals, absorbed by some dielectric materials and transmitted through other materials without significant losses. 

The helix slows down the propagation of electrons as these travel down the tube. The electrons bunch, and reinforce the voltage in the helix, which creates amplification (Courtesy: Thales Electron Devices)

Many R&D centres in India are actively inrolved in the advancement of microwave tubes. These include:

1. Central Electronics Engineering Research Institute, Pilani
2. Central Scientific Instruments Organisation, Chandigarh
3. Central Glass and Ceramic Research Institute, Kolkata
4. Central Mechanical Engineering Research Institute, Durgapur
5. Bharat Electronics Ltd, Bengaluru
6. Vacuum Electronics Devices and Application Society
7. Microwave Tube Research and Development Center, Bengaluru
8. Center of Research in Microwave Tubes, BHU
9. College of Engineering and Technology, Moradabad
10. Institute of Plasma Research, Gandhinagar
11. Society for Advanced Microwave Electronics Engineering & Research, Mumbai 

Microwave tubes have potential applications in radar, electronic warfare and communication systems. Air-traffic-controlradars, military radars, ground penetrating radars, imaging radars, UWB radars, cloud radars and space debris radars are some types of radars that use microwave tubes. Multi-beam jammers, phase-array jammers, and ultra-high-frequency and ultra-wide-bandwidth jammers used in electronic warfare also use microwave tubes. Clouds can be seen by microwave. These tubes play a role in climate forecasting and some medical applications (used in the diagnosis of hyperthermia) as well. Besides, microwave has its utilities for common man in the form of microwave heating and microwave protective gear/wall paper/furnishing.


Basic principle of microwave devices

The efficiency of conventional tubes is largely independent of the frequency up to a certain limit. When the frequency increases beyond that limit, several factors combine to rapidly decrease the tube’s efficiency. The high-frequency effects in conventional tubes are circuit reactance (inter-electrode capacitance, lead inductance), transit-time effect, cathode emission, plate-heat dissipation, power loss due to skin effect, radiation and dielectric loss.

Microwave devices

Conventional devices. Klystrons, magnetrons, traveling-wave tubes, backward-wave oscillators and crossed-field amplifiers New-generation devices. Cyclotron resonance devices (gyrotrons, gyro-TWTs and klystron-BWOs), Cerenkov radiation devices (magnetrons/BWOs/TWTs, orotrons, magnetically insulated line oscillators), Doppler effect-based devices (free-electron lasers, ubitrons, cyclotron auto-resonance masers), space-charge devices (virtual cathode oscillators) and multi-beam devices

Tubes that are efficient in the microwave range usually operate on the theory of velocity modulation. The microwave tube uses transit time in the conversion of DC power into radio-frequency power. The interchange of power is obtained by using the principle of electron velocity modulation and low-loss resonant cavities in the microwave tube.

Velocity modulation is define as the variation in the velocity of a beam of electrons caused by the alternate speeding up and slowing down of the electrons beam. This variation is usually caused by a voltage signal applied between the grids through which the beam must pass. The directions of the electron beam and the static electrical field are parallel to linear beam tubes. Against this, the field sinfluencing the electron beam stand vertically by the electron beam at the crossed-field tubes.

Magnetron—a microwave device
Magnetrons are a special form of diodes. Electrons move between the cathode and anode in a curved fashion, and thus the electric field and the magneti field are normal to the electron beam. When an electron is slowed down by an electric or magnetic field, it gives up energy, making the field stronger. If an electron’s speed is increased by an electric or magnetic field, it weakens the field.

An amplifier tube circuit that generates radio frequency signals is called an oscillator. A resonant circuit consisting of an inductor (coil) in parallel with a capacitor determines the frequency and wavelength of the oscillator. The lesser the number of turns in the coil, the smaller the capacitor plates and the higher the radio frequency that the oscillator generates. 

Magnetrons have a central cylindrical cathode surrounded by an anode in the form of a thick cylindrical shell. Top and bottom plates form the remainder of the vacuum envelope. These plates are placed between the poles of a strong magnet.

The controlled resonant circuit problem at microwave frequencies is solved by using hollow metal cylinders as a resonator. The round cylinder walls are similar to a one-turn coil and the cylinder end plates are like a very small capacitor. These cylindrical resonators are called microwave cavities. By moving one of the cavity’s end plates in or out of the cylinder, the frequency of the oscillator can be tuned. The cylinder must be about a wavelength in diameter and about one-half wavelength long at the resonant frequency. Energy can flowin and out of the resonator through a hole in the cylinder wall. 

Future technology

1. Multiple-beam klystrons for synthetic-aperture radars and missile seekers 2. TWTs for towed decoys 3. Microwave power modules based transmit/receive modules for phased-array radars 4. High-power microwave devices for directed-energy weapons 5. Gyro TWTs for radar applications 6. Vacuum microelectronics based microwave devices (TWT on a chip) 7. Tera-hertz devices for secure high-data-rate communication, imaging and radar 8. Microwave power beaming rectennas 9. Microwave propulsion 10. Microwave plasma chemistry 11. Microwave-generated artificial ionospheric mirrors (over-the-horizon radars and battlefield illumination)

The microwave fields from the resonators extend into the region between the cathode and anode. A strong magnetic field makes the highspeed electrons move such that these don’t reach the anode and return to the cathode, unless slowed down by giving up energy to a cavity electric field.

If the electrons arrive at the wrong time, these take energy from the microwave field, speed up and spiral back t the cathode. At the correct voltage and microwave frequency, the electrons move at the correct velocity to continue to loose speed and give up most of the energy to the microwave field before the impact on the anode. 

Other devices

Magnetron oscillator was the first device developed that was capable of generating large powers at microwave frequencies. Later, improved devices such as travelling-wave tube amplifiers (TWTAs) were developed for use in microwave systems. Yet, magnetron production continues for use in micro-wave ovens. 

Cross-field amplifier (CFA) is another microwave power amplifier. It is a cross between TWTs and magnetrons in its operation. It has a magnetron structure to provide interaction between crossed DC electric and magnetic fieldson one hand and RF field on he other. It also uses a slow-wave structure, as in TWT, to provide a continuous interaction between the electron beam and a moving RF field.

The backward-wave oscillator (BWO) is also a microwave-frequency and velocity-modulated tube that operates on the same principle as the TWT. However, a travelling wave that moves from the electron gun end of the tube towards the collector is not used in the BWO. Instead, the BWO extracts energy from the electron beam using a backward wave that travels from the collector towards the electron gun (cathode). 

Solar Power FAQ's (Frequently Asked Questions)

1. Solar panels cost -
650 kwhr / 30 days = 22 units per day. If you want to generate one unit, you need 200 watt solar panel

To generate 22 units you need 22 x 200 = 4400 watts panels

taking in to inefficiencies of the total system we need 5000 watt of panels

Cost of the panel is Rs 60 per watt

5000 x 60 = Rs. 3,00,000.

2. Battery -

To store this in to the battery (assuming that all the eneregy generated by the solar panel will be required to store in the batteries for using it in night time) you will need batteries that can store 25 Kwh of electrical energy.

Th cost of the Tubular Battery battery will be Rs. 10,000 per kwh

Total cost of the lead acid batteries will be -

Rs. 10,000 per kwh  x 25 kwhr = Rs. 2,50,000.

Now it is not possible to charge these batteries within 5 to 6 hrs when sun is shining. You need 4 times the normal capacity.

So the total cost of the batteries will be -

Rs. 2,50,000 x 4 = Rs. 10,00,000.

3. Charge controller, Inverter & Installation-

Apart from battery and solar panel you will need charge controller and inverter and other hardware and installation and commissioning that will cost you another Rs. 2,00,000.

So the total cost will be Rs. 15,00,000 (see above 1+2+3) for totally full proof system. You will see that main cost is of batteries. It depends on whether you need 24 hrs backup, 8 hrs backup or as per your needs.

So we can reduce the cost by reducing the batteries.

Solar Power FAQ's (Frequently Asked Questions)

What is solar energy?

Solar energy takes advantage of the sun's rays to generate heat or electricity. It is an infinitely renewable resource and unique for its ability to generate energy in a quiet, clean, and consistent manner. Can't beat the sun for being oh-so-cool!

How do solar photovoltaic cells work?

In layperson terms, photovoltaic cells are comprised of a semiconductor material such as silicon. Added to the silicon are the elements phosphorous and boron which create conductivity within the cell and activate the movement of electrons. The electrons move across the cell when activated by the sunlight's energy into the electrical circuit hooked up to the solar panel.

For more information, visit our Photovoltaic Electric Systems page.

What is the difference between solar panels versus building integrated photovoltaic products?

Solar panels are flat panels of photovoltaic arrays mounted on a roof or a pole to capture the sun's rays. Building integrated photovoltaic materials are PV arrays that are integrated into the building material itself, primarily windows, roof tiles, or walls. Solar panels work well for retrofits or remodels while BIPV are appropriate for new construction or a major renovation.

How much does a solar electric power system cost?

A 2kW solar electric system will cost approximately $20,000. That total includes the cost for all components – solar panels, panel mounts, and inverter – and labor associated with installation. It does not however, reflect all the avoided costs, such as the tax breaks and the credits received through net metering.

Go to our Solar Power Cost page for more information, visit our Solar Calculator page to get an estimate, or find a solar power installer to size and price the right system for you.

How much will I really save on my utility bills from a home electric solar power system?

Of course this is a relative question. It depends, in part, on how much electricity you use and how efficient the appliances are that you operate. That said expect to generate excess electricity in the summer (when days are long) which can potentially offset the energy you use from the grid in the winter. A combination of energy efficient appliances and light bulbs can help reduce your homes energy bill by over two-thirds.

Find out more about the costs and potential savings from a residential solar power system in our Solar Power Cost section.

What's the difference between solar photovoltaic and solar hot water systems?

While both types of solar systems capture energy from the sun, solar photovoltaic systems use photovoltaic panels to produce electricity. Solar hot water, or thermal, systems capture sunlight to heat water for domestic use, to heat a swimming pool, or for a radiant heating system.

What are solar hot water systems?

Solar hot water systems, broadly termed solar thermal systems, use the sun's energy to heat water. Solar hot water systems can be used to heat a hot water tank or to warm a home's radiant heating system. Swimming pools and hot tubs use a modified solar hot water system for heating water.

Find more information on how solar hot water systems work in our Solar Thermal section.

Can I use solar power to heat my home?

Absolutely! Radiant heating applies solar thermal technology. Transferring solar energy through pipes into an under floor radiant heating system is a wonderful way to stay warm. Radiant floor systems are typically 40 percent more efficient than their forced air counterpart and can be zoned to match thermal comfort to each room.

Find more information about radiant heating in our Solar Heating Systems section.

How much maintenance do solar energy panels require?

Solar photovoltaic panels require little maintenance – no need to wash or dust. It is, however, important to place panels where they will remain clear of shade and debris. Thus you will have to wipe them off if too much snow or leaves fall on them.

Solar hot water collection arrays don't need much attention either. It does help to periodically use a window wash brush, biodegradable soap, and water to clean the tubes.

Can I use a financing system?

Yes. Consider using a home equity loan for the purchase and installation costs of a solar photovoltaic or solar hot water system to take full advantage of federal tax deductions. Solar energy systems are viewed as a major home energy savings upgrade and there are financial tools out there that reward you for your efforts. Remember, installing a solar energy system is comparable to any other upgrade you might do to your home, such as installing a new deck or remodeling a kitchen.

Find more information about ways to finance your home's solar power system in our Solar Financing Options section.

Do I need special insurance requirements?

Standard homeowner's insurance policies usually suffice to meet electric utility requirements. Electric utilities usually require that homeowners who take advantage of net metering sign an interconnection agreement.

Will I need a building permit to install a solar energy system in my home?

Yes. You'll need to obtain building permits to install a solar photovoltaic or solar hot water system. Similarly, building, electrical, and plumbing codes also apply. That said, residential solar power systems do not use "radical" building techniques and most jurisdictions have building codes that fully embrace solar energy technology. Solar professionals will roll the price for permits into their cost estimate.

What if I'm the first person I know to install a photovoltaic system on my home?

First off, congratulations! Secondly, there are plenty of resources out there. Most solar electric building standards are based on the National Electric Code (NEC) Article 690. If you happen to be one of the first in your area to install a solar PV system, you can work with your contractor and local building officials to successfully install your photovoltaic system. NEC Article 690 spells out the requirements for designing a safe, reliable, and code-compliant system.

Locate a Solar Installer in your area to help you with your project.

When should I seek a solar professional?

Although solar energy systems work in parallel with conventional residential electrical and plumbing systems, there are quirks in the process well suited to seeking out professionals who specialize in solar power installation. Solar installation professionals can help you determine the type and size of system most suited for your needs.

What should I ask a solar professional installer?

Solar professional installers can take the guess work out of installing a solar power system. Whether you are considering solar photovoltaic, solar hot water, or solar heat for your pool, a solar pro can help you determine the type and size of system that will work best and guide you through the process.

Why is it important to get multiple bids?

As with any major purchase, it's helpful to compare costs and information. Seeking information from multiple professionals can provide constructive advice, set realistic expectations, and help you fine-tune the design that will work best for your application.

How can I calculate the cost and payback time from a solar power installation?

You can estimate how much a solar electric or solar hot water system may cost if you determine your current energy needs and costs and compare against your future anticipated use. Once you have a sense of how much energy you use, you can evaluate the cost of purchasing and installing one or both of the technologies.

Luckily in today's market you can take advantage of multiple federal, state, and local tax credits, rebates and other financial incentives that create attractive and competitive prices for solar PV and hot water systems.

Find more information in our Solar Power Cost section.

How long will it take to install a solar power system in my home?

Planning, configuring, and doing any custom ordering for your solar energy system can take up to a few weeks. However, the installation process itself can typically be completed in only a few days time, in many cases even less.

How can SolarEnergy.net help me shop for solar?

SolarEnergy.net saves you time, money, and headaches by connecting you directly to the best solar power companies in the country. SolarEnergy.net only works with experienced solar professionals and firms with a track record of success and satisfied customers. We encourage you to look around our site for all the information you need on solar energy installation.

When you're ready, all you need to do to get started is tell us about your project, and you can be assured you'll receive competitive bids from the very best companies in your area.

SolarEnergy.net's service is completely free to use and there is no obligation attached. Start Immediately!

What components do I need to install a grid-tied solar electric system?

You will need a photovoltaic array to capture the sun's energy, an inverter to convert the direct current (DC) produced from the photovoltaic cells into alternating current (AC) used by your home, and a house utility meter – called a net meter – that can record both the electricity produced from your home's power system as well as any power you may use off the grid. These three system components are then connected through a series of wiring. The photovoltaic panels are secured to your roof with panel mounts or are installed on poles that can be adjusted for sun angle.

What is a net meter?

Net meters look very much like other outdoor meters with one notable exception – they spin both forwards and backwards recording both the power produced and power used.

Do I need battery backup for my solar panels?

Probably not – a backup battery bank can add as much as 25% in cost to a residential solar PV system. It's not necessarily more efficient either – a same sized solar array will yield about 7–10% less energy if it's battery-tied than its grid-tied counterpart.

Though you will remain tethered to your local utilities' grid, you will not have to worry about not generating enough power. You also gain the advantage of offsetting rising utility costs. Most solar photovoltaic experts do not recommend adding a backup battery system unless there is concern about a long utility outage or the residence is in a remote location.

How much space do I need for a solar photovoltaic system?

In bright sunlight, a square foot of a conventional photovoltaic panel will yield 10 watts of power. That's a helpful rule of thumb for calculating a rough estimate of how much area you might need. For example, a 1000 watt system may need 100 – 200 square feet of area, depending on the type of PV module used.

How many solar panels do I need for an electric solar power system?

The size of the photovoltaic system is correlated to your home's energy-use needs, available space for a system, and overall costs for the system components and installation. Solar contractors in your area can help determine the best size for your solar photovoltaic system.

Find out how to estimate your home's solar electricity needs by checking out our Solar Power Cost section.

To find a local solar installer, use our Solar Installer Directory.

How much shading is too much for solar photovoltaic panels?

Unfortunately shading a photovoltaic system dramatically decreases its output. Just shading the bottom row of wafers alone amounts to an 80% reduction in efficiency. So above all, don't shade your array!

How do I know if solar panels will work on my home?

Take a look at the position of your home on its lot – and particularly your roof. Ask the following questions:

1. Is there good southern exposure? Orienting solar panels to the south maximizes the effectiveness of energy collection.
2. Is the exposure free of trees or buildings that could shade the panels or drop debris on them? Shading photovoltaic panels dramatically reduces their effectiveness.
3. What is the pitch of your roof? Most roofs, from flat to 60-degrees can accommodate photovoltaic panels.

Do I need to have south facing exposure to have a solar energy system?

Although southern exposure increases the effectiveness of a residential solar power system, your home may still work for solar power without having south facing exposure. Seek advice from a professional solar designer or installer to ensure success.

What other factors are important to consider when installing a home solar energy system?

The location of your home and the local climate will play into where you place and how you install your solar electric or solar hot water system. Wind speeds, heavy snow loads, and salt water can all affect a solar array. Understanding how those inputs effect performance will determine the types of mounts or how the arrays are angled. A solar pro in your area is likely quite knowledgeable about your local conditions and can help you design that works well for you.

1. Solar panels cost -

650 kwhr / 30 days = 22 units per day. If you want to generate one unit, you need 200 watt solar panel

To generate 22 units you need 22 x 200 = 4400 watts panels

taking in to inefficiencies of the total system we need 5000 watt of panels

Cost of the panel is Rs 60 per watt

5000 x 60 = Rs. 3,00,000.

2. Battery -
To store this in to the battery (assuming that all the eneregy generated by the solar panel will be required to store in the batteries for using it in night time) you will need batteries that can store 25 Kwh of electrical energy.

Th cost of the Tubular Battery battery will be Rs. 10,000 per kwh

Total cost of the lead acid batteries will be -

Rs. 10,000 per kwh  x 25 kwhr = Rs. 2,50,000.

Now it is not possible to charge these batteries within 5 to 6 hrs when sun is shining. You need 4 times the normal capacity.

So the total cost of the batteries will be -

Rs. 2,50,000 x 4 = Rs. 10,00,000.

3. Charge controller, Inverter & Installation-

Apart from battery and solar panel you will need charge controller and inverter and other hardware and installation and commissioning that will cost you another Rs. 2,00,000.

So the total cost will be Rs. 15,00,000 (see above 1+2+3) for totally full proof system. You will see that main cost is of batteries. It depends on whether you need 24 hrs backup, 8 hrs backup or as per your needs.

So we can reduce the cost by reducing the batteries.