Wednesday, 16 April 2014

Solar Stills - Obtaining Pure Water using Sun's Heat

The above video shows a simple method to obtain pure (almost drinking-quality) water, from impure water, using just the sun's heat. The concept is quite simple: Water evaporates due to sun's heat, leaving all dust/debris below. Due to the plastic cover, the water vapour cannot escape into the atmosphere. So, it gets condensed back into water, slides towards the middle and then drops into the empty smaller container placed in the center of the larger bowl containing the impure water. 

The plastic cover ensures that sun's heat gets trapped within the container (due to glasshouse effect) and heats up the water to form vapour. This principle is the same as pure water evaporating from the sea (leaving off all the salts), forming clouds, and falling back into the earth as rain. As you can see in the video, the set-up is simple and it could be very useful in places where water filtration is not possible. In countries closer to the equator, this should work for most months, not only during summer. This method of obtaining pure water using sun's heat is referred to as solar stills. 

The solar still can also be used to make water, if there is no water available (emergency situations). The second video (embedded above) shows how you can do that using just a simple plastic cover, some edible plant leaves, a container, and some stones. Actually, our soil stores some moisture that evaporates into water vapour (if enough - sun's - heat is available) which evaporates & condenses back into water. This water can be trapped in a container placed at the center (just below the central stone on the plastic cover). So, next time you find yourselves stranded in an island or sea or forest or where ever, you know how to get pure drinking water! 

Thursday, 10 April 2014

Solar Impulse 2: An Airplane to Fly around the World using Solar Energy!

Certain inventions spark off a revolution - the Solar Impulse airplane, that is totally powered using solar energy, is one of them. Earlier, the Solar Impulse team had tested the Solar Impulse 1 airplane which successfully completed the first 24-hour non-stop journey & traveled across USA, Africa & Europe, using just solar energy.

Now, the same team has announced the Solar Impulse 2 airplane, also powered exclusively using solar energy, that will circumnavigate the world (in 2015). This one is expected to come to/halt in India, as well. 

Whether you admit it or not, the future is for such green technologies. We are in the brink of over-use and abuse of existing resources that if our 'development' spree continues in the same speed (or faster), there will be nothing left for anybody. Green technologies that use renewable energy are our only hope and the Solar Impulse 2, though symbolic, is a powerful indicator of the direction which future technologies will be forced to take. 

The very idea that an airplane can circumnavigate the globe using just the solar energy, gives us a lot of hope. Solar Impulse is not about applying technology to create one airplane - it is more about being a testament to the point that if an airplane can be powered using solar energy, our homes, offices, cars, buses, trains, etc. can all be easily powered by solar power! 

That is why an innovation like this is very important. It is path-breaking and revolutionary. I wish I could see this airplane directly, when it comes to India. I will definitely try my best to do that. 

If you've not been taking renewable energy seriously until now, it's high-time you did. 

Renewable energy is going to disrupt the way we live. 

Solar Impulse 2 is the living proof. 

More details: Solar Impulse website

Monday, 31 March 2014

Contest: Why will you/will you not Install Solar Panels at your Home?

This week, be ready to put your thinking/writing caps on. I have decided to conduct a contest on the topic, "Why will you/will you not Install Solar Panels at your home?". 

What you need to do:
  • Write an article/essay telling us why you will (or) will not install solar panels at your home. Word count: As you see fit.
  • You can write and send the document (MS Word, Open Office or Text) to - solarwindhydroenergy[at]
  • If you don't want to write, you can upload an image/poster, audio clip or video clip (on soundcloud, youtube, etc.) and send the URL (web-address of your creative work) to the above mentioned email address.
What you get:  
  • All essays/ articles/ creative-works will be featured/published in It will be sent via email/RSS to all subscribers and will be visible to people vising the homepage. You can add a byline about yourself/your business/your passions/your social media profile/your blog URL, etc. at the end of the article, if you want to.
  • Three of the best essays/articles will receive 500 rupees gift voucher from Flipkart, each. Selection will be done by the administrator of this website based on how well the article has been thought of/written and how creatively you convey the message. 
  • The administrator of this site has the final say on whether to publish your articles or not (and) to determine which article(s) get the prize. An article maybe rejected if it does not pertain to the spirit of the contest. The administrator may edit your articles (if required). 
Note: The contest is open to everyone, but the prizes will be given only to Indian nationals who live in India. People from other countries can also participate to get their articles featured/published on this website.

The contest will be open from April 01 - June 30, 2014. The three prize winners will be announced on this site before July 10, 2014. You can send an entry even after that date if you want to get your article/video published on this website. 

The copyrights for your entries will remain with you. But, by participating in this contest, you agree to give permission to the administrator to publish your articles, images, audio, video on this website and promote it in social media. You can, however, republish it elsewhere (on your blog, social media, etc.) anytime. 

So, what are you waiting for? Go ahead, write or record and send your entry ASAP. The articles will be published as they are received. In case there are two similar articles, the second one will be rejected.

Thanking you,

Rajesh K
Administrator & Blogger -

Tuesday, 25 March 2014

Installing Solar Panels over Canals: Win-Win Situation!

The installation of solar panels over the Narmada Canal (water body) in the Indian state of Gujarat offers an interesting case study because it solves multiple problems and creates a Win-Win situation. 

What is the Narmada Canal Solar Project?

The Narmada Canal is a manmade water body that transports water from a river to many rural areas for farming, drinking, etc. The Gujarat Govt. (in India) decided to install solar panels (as shown in the above video) over the top of the canal, partially covering the water (below) for a distance of about 1 KM. The rated capacity of installed solar panels comes to around 1 MW and it provides electricity to 7-8,000 houses around the area, serving 20-25,000 people. 


  • Provides electricity to rural areas that were not connected to the grid (earlier). Mainly used for lighting and cell phone charging. Rated capacity: 1 MW. 
  • Saves around 90,000 liters of water as solar panels cover the top of the canal (preventing some of the sun's heat from passing below), and windshields prevent wind from carrying away the water vapour formed just over the water. There is a gap between each row of solar panel where sunlight passes through, but the over-all sunlight exposure (and evaporation) is reduced. 
  • Prevents the formation of algae (to a certain extent, as they need sunlight to grow) that could choke pipelines drawing water from the canal. 
  • Keeps the solar panels relatively cool (due to the running water below it) and hence increases the energy output. 
  • Saves a lot of space as empty lands might have otherwise been required to fix all these solar panels. That saves a considerable amount of money (required to buy land), as well. 
This project was executed by SunEdison. Check this pdf report to get further details on this innovative project. Don't you think it's a good idea to cover water bodies (canals) with solar panels in order to generate electricity and save ground-space? I think it's a good idea as long as it is near to the rural areas (that are not connected to the grid) and there is a substation somewhere nearby to evacuate all that power immediately. 

Monday, 10 March 2014

Reducing Energy Consumption by Appliances = Increasing Solar Panel Efficiency?

Think about this: Many companies in the renewable/solar energy field are concentrating only on increasing the solar panel efficiency, but not about optimizing the energy consumption by electrical appliances that are going to use the power generated by the solar panels. In effect, both give the same result. Or wait. Will increasing the energy efficiency of appliances make a bigger difference? 

I met Dr. R. Ramarathnam of Basil Energetics Pvt. Ltd, Chennai, India, who has introduced Super Energy Efficient Products (electrical appliances) that can utilize both AC & DC current (so that they can run using electricity from the mains and solar panels, respectively). They have introduced an Inverterless solar system that powers the above mentioned super efficient appliances. Also, the appliances are soft-starting and hence they don't require a huge amount of current during start-up.

Basil Energetics has also developed a solar controller system that alternates the power supply (to the appliances) between the mains and solar panels, depending on the amount of power generated by the solar modules. 

What does all this mean for the end user?

It means, users can power (high power demanding appliances like) air-conditioners, refrigerators through solar panels, as the electricity requirement for these super efficient appliances are considerably lower than normal ACs and fridges available in the market (that are generally kept out of solar power systems).  

The above photo shows the iGrid, the solar power controller installed in The Rain Center, Chennai. This controller alternates the power supply between the solar panel input and the grid input. If the solar power is sufficient, all the appliances are powered using solar panels. If the solar power is lower, solar panels power as many appliances as possible and the remaining power is drawn from the grid. If the solar panel output is nil (during nights, for example), all the power is drawn from the grid (mains). 

The above photo shows iChill, their super efficient air conditioner. According to the company, their 1.5 Tonne air conditioner consumes just 900W - 1300W, while even BEE 5 Star Certified air conditioners available in the market consume a minimum of 1800 W. These air conditioners can work both on AC & DC current, hence avoiding the use of an inverter (that converts DC power generated by solar panels into AC power required for normal appliances). 

The above photo shows iFreez, their super efficient refrigerator. According to the company, their 330 Liter fridge consumes 100W initially and within an hour the power consumption reduces to 70 - 40W. But even a normal 165L refrigerator in the market consumes 145W of electricity. The iFreez can also work using both AC and DC inputs. 

The above picture shows a LED lamp that is inherently super-efficient and consumes lesser power than tubelights or CFL lamps. It seems, they also have LED tubelights and energy efficient fans (that consume 25W (vs) 55W for BEE 5-star rated fans). 

Since these appliances consume less electricity than normal appliances, the solar power requirement (and hence the rating/cost of solar panels) is also lower. Besides, many solar power systems do not connect to/power air conditioners and refrigerators, as these appliances are energy guzzlers. But in a hot country like India, these two appliances are critical, especially in summer. 

According to them, the power factor of their appliances are closer to 1 and hence the current lost (due to that) is minimum. Also, since their appliances can handle voltage fluctuations, they do not require a stabilizer, which in itself consumes some power (if present). 

Batteries can be supplied (at additional cost). Otherwise, this system eliminates the batteries as well, in addition to eliminating inverters! I feel (smaller capacity) batteries maybe required to power appliances during power-cuts (In Chennai city powercut has been around 1-2 hours).

Edited to add (after receiving feedback from company officials): Back up by battery is possible and is given as add on option. Due to the super efficiency of the appliances and absence of starting current, the AH (Ampere Hour) rating of the battery comes down by as much as 67%.

I feel, if this system can interact with the grid and feed excess power to it, it will be beneficial to the consumers. At present, any excess power generated, I guess, is grounded and hence lost. But connecting to the grid using smart meters depends on the state electricity policy. Right now, some pilot projects have been announced, and (hopefully) more solar systems maybe allowed to draw power from/export power to, the grid in the future.

Also, many consumers may have existing air conditioners and refrigerators. Those cannot by powered by this system. Since this system comes as a package (solar panels, controller, appliances, etc.), consumers need to consider what can be done with their existing appliances (if any).

Since this system does not supply power in the night (no sun), appliances are totally dependent on the grid. In summers, since many air conditioners draw maximum load in the nights (for residential areas), the strain on the grid is also huge which result in low-voltage scenarios. If solar power could replace grid power during nights, at least for three months in the summer, it will be very useful (both for the consumer and for the EB dept). 

If you're wondering why I didn't publish the photo of the solar panels, well, here it is - 

I couldn't take a picture from the top to show you the shining blue solar panels! 

I thank Dr. R. Ramarathnam of Basil Energetics Pvt. Ltd. for explaining the technical details of the system to me, and Dr. Sekar Raghavan for allowing me to take pictures of the system installed in The Rain Center, Chennai. For further information, you can contact Basil Energetics @ +91 44 43111289.

Please note: All the info given in this article is based on what was conveyed to me by the company officials. I have not verified any of the technical info presented here. Consumers are encouraged to verify the info and test the equipments (if required) before making any purchase decisions. This article is only for informational purposes and is not a testimonial to the company or their products. 

Monday, 24 February 2014

Tracking the Sun (for Solar Panels) Doesn't Always have to be Complicated!

SunSaluter, the solution explained in the video embedded above, is a great way to increase the amount of electricity generated by individual solar panels by using simple materials (like PET water bottles filled with water). Basically, it enables the solar panels to face the direction of the sun without using complicated trackers or electricity.

One good way to increase the efficiency/solar power output of a solar panel system is by rotating the solar modules to always face the sun, as it moves from east to west, throughout the day. Mostly, solar panels are either left at a fixed position and the lower yield is tolerated, or solar trackers are attached to individual solar panels that rotate them to face the sun always. 

The issue with solar trackers is - they are expensive, consume some electricity themselves, and they make the system more complicated. Needless to say, maintenance will require trained personnel and replacement parts need to be available locally. In short, even though solar trackers increase the energy output/energy efficiency of solar panels considerably, there are some inhibitors that prevent them to be used in all solar projects. Chief of them being increased capital costs. 

But the solution created by SunSaluter, is something to look forward to, especially in developing nations like ours. Look at how SunSaluter works from here. See how simple the whole set-up is: It's basically a water clock that automatically tilts the solar panels, as the flow of water flowing through the plastic bottles is controlled using a valve. In addition to generating more electricity from every solar panel (up to 40%), this system also helps filter impure water and provide good drinking water. It will be an excellent choice for rural areas, that lack either. 

But in addition to serving rural areas, urban areas and small solar generation units over houses and companies might also benefit from such a solution. Think about what we have in abundance - low-cost labor! Hence, filling some bottles with water and hanging them in their position everyday doesn't require much labor. In the houses, the home owners themselves can do it and in small solar generation sites, watchmen or anyone else can do it. 

The thing is: If 40% additional electricity can be obtained without any (considerable) additional investment, why not take some (little) additional effort? If some University can develop on this system further and make it easier to operate and customize it to our requirements, this solution will be very useful to us. It will be better if the people who invented it can customize the solution to suit the requirements of different countries and bring it on a commercial scale. 

Wednesday, 19 February 2014

Why not give a Loan (instead of donating) for Renewable Energy projects?

There are many individuals and organizations who want to give donations to renewable energy projects, in order to create a better future and to increase renewable energy adoption. I appreciate their motive, donations do increase renewable energy adoption. 

But, are donations good/sustainable on the long run? What if the recipient becomes dependent on your donation? Does it not encourage malpractices? What about accountability, do you or your organization keep a track on the projects you have donated for, and ensure that the money is actually used to promote renewable energy usage? Many times, it's difficult to track/check these factors. 

Instead of donating to a renewable energy project, why not give a loan?

According to what is mentioned on their website, is a service functioning in India that enables people to lend as much money as they can (starting from Rs. 500), which will be returned by the borrowers over a period of time (which can vary depending on the project). Mostly individuals or small groups, who don't have upfront capital investment for buying things like solar lanterns, etc. are selected by's partners and loans are disbursed to them. Field executives (from partner's side) are in charge of repayment collection, and the installment money will be repaid to you as they are collected. 

The entire process happens online (for lenders) - this is a good example of crowd-funded micro-financing, in action. They charge some interest from the borrowers, but according to what I understand from their site, most of the interest amount goes towards their operation costs. So, basically you'll be giving interest free loans (if my understanding of what is provided in their website is right).  

And also, there are no repayment guarantees. Even though all the partners have a 100% on-time repayment track record (as mentioned on their website, at the time of writing this article), there is a chance that some borrowers might default/delay repayments. The current 100% repayment should have been possible because of some buffer amount the organization/partners might be having (my guess). Otherwise, achieving that 100% on-time repayment, is very difficult. Practically speaking. 

Have a look at the projects mentioned on this page (click on 'energy' on the left hand side, to see renewable energy based projects - mostly) and see if you would want to help any of the recipients with a small loan. Of course, my website is not connected with in anyway, and this post is not to canvass for their services. Have a look at all the terms & conditions mentioned there and then decide for yourself. Please make sure you understand all the risks involved, before proceeding. 

The point of the post is, why not lend money, make the borrowers accountable for the money that they are spending and make sure that your money is spent for the right/preferred, cause? also has a feature that allows you to re-lend the money that is collected on your behalf (just in case you want to encourage more projects) and treat your money like a donation, but not actually a donation! 

I thought is an interesting (and potentially impactful) initiative that could enrich the lives of many economically disadvantaged people, and increase renewable energy adoption (at least partly). Hence I am writing this article. Please be sure that I didn't receive any incentive/compensation for writing this article.