From the Sun, in less than an hour mankind receives all the energy we need in a year. If the solar energy on less than 5% of the Sahara was collected, it would meet the global energy consumption projected for the end of the century. This fuel is inexhaustible, clean and free.

We all hope that President Obama has the kind of vision which initiated the Marshall Plan or the Moon Landing. It is that kind of vision that is needed to create millions of jobs while not only revitalizing the housing industry, but also making us energy independent. One important step towards meeting these goals is the building of energy-free solar homes.

In the southern half of the United States, a 20% efficient solar collector will yearly generate about 400 kWh/m2 of electricity (Figure below). Therefore, if 100 m2 collectors were installed on 10 million homes, the energy saving would exceed the total imports from the Persian Gulf and if 100 million such roofs were installed, they would meet the total electricity consumption of the nation.

(Courtesy of the National Renewable Energy Laboratory (NREL).

To make solar energy continuously available requires storage. The means of storage can be thermal (hot oil), chemical (hydrogen) or electric (batteries or on the grid). In locations where the home is already connected to the grid, this provides a convenient method of storage. The grid makes it possible to send the excess solar electricity to the grid when the level of insolation is high and take the electricity needed from the grid when it is not. In this “net metering” mode of operation, when solar energy is in excess, the home’s electric meter is “running backwards” and the home is accumulating an electricity credit. This credit can than be used at night or when the sun is not out without any cost to the homeowner.

Many utilities are willing to provide this “net metering” service, because excess solar energy is usually generated during peak periods (when the air conditioning loads are high) and therefore, by accepting it, the utility can “shave” its peak demand and thereby operate more profitably. Where either the grid or this “net metering” service is not available, the solar energy can also be stored in hydrogen by the use of a reversible fuel cell (RFC). This device makes hydrogen from the excess solar energy when the sun is out and makes electricity from the stored hydrogen when solar energy is not available.

To make a home completely energy free, the area of the solar collector has to be sufficient to also provide the energy needed for other purposes, such as transportation. Depending on the number of cars and on the commuting distances of the residents, the recharging of the electric car batteries might require the doubling of the solar collector area.

The cost of conversion from today’s exhaustible energy economy to the coming free, clean and inexhaustible energy economy will determine the speed of this conversion. Today, the cost of pohotovoltaic collectors ranges from $5 to $10 per “peak solar watt”. This cost has been dropping by about 5%/yr and once mass production starts, it is likely to drop at an even faster rate, similarly to the reduction experienced when the mass production of computers started. (Some suppliers using nanosolar technology are already projecting $1/Wp in the near future).

Thin cell collectors require less expensive materials to build and use less of them. They are made from a thin film of amorphous silicon on plastic and are used on the roofs of private homes or commercial buildings. This results in a substantial cost reduction. Such flexible strip collectors are already available (Figure) and are used to cover the roofs with solar shingles. The National Renewable Energy Laboratory in March 2008 reported a world record in thin-film solar cell efficiency (19.9%), nearly tying the record for traditional photovoltaics (20.3%).

(Courtesy of NREL/DOE)

The time for debating the feasibility of solar energy is over, now it is time for action. What is needed are hard cost and performance data based on the use of mass produced and state-of-the art components. To prove that it is time to convert to this inexhaustible energy economy, we not only need solar roofs, grids, electric cars and solar–hydrogen demonstration plants! We also need statesmen. We need leaders who care about the future of the planet and the future of our grandchildren. We need leaders who are ready to lead this, the third industrial revolution. We need leaders with vision, commitment and the conviction, that the United States is still the leader of the planet, that she can stop the trend towards wasting our resources on energy wars and instead can lead a global Marshall Plan to make our peace with the planet.

It is debatable how much time we have before our fossil and uranium deposits are exhausted. It is also debatable how much climate change we can live with or how much of our economic resources should be devoted to stabilizing and reversing mankind’s growing carbon footprint. What is not debatable is that our resources are exhaustible and that we must not give reason to our grandchildren to ask: “Why did you not act in time?”

Béla Lipták

I was very impressed by your what you have written, more importantly by what you have done. I am not young 62 years old but your account is inspiring.
I wonder if you had thought of an immediate change you can bring about in the Indian transportation Sector. I am sure in your tarvel from Chennai to Delhi, you would have crossed a number of smaller towns where the main mode of transportation is the ubiquitous autorickshaw apart ferom large buses. thes autos are pollutres running on diesel/petrol/gas carbon and notrogen polluters of varying degrees.
Imagine a situation when you could retrofit these autos with battery driven motors and the discharged batteries could be exchange for fully charged batteries avialable in kiosks like filling stations. These kiosks would be fed with electricity generated through intermittent sources such as solar or wind. Small power plants would only charge batteries. Even if locational factors do not merit location of these power stations near the kiosks, they could feed into the state grid and swapower. At an average price of Indin rupees [ INR] 8 per kwh of electricity , it would cost 0.5 INR per km if one were to take the REVA as the basis. The weight of the unit would be comparable using the tare weight and payload together.
There are about 50000 autos coming in every year and and more rhan amillion on the roads. If a selected town is taken as the test bed and this exercise carried out, the idea could catch on. Financing retrofits and the small power stations could be partilyy helped by the carbon credits which would accrue to the exercise
I would love to get your reaction

The IYCN continues to impress and inspire me.. You all carry such a beautiful, positive vision!

Keep us posted on the journey. I look forward to reading more about it soon!

- Christine