Solution to climate change

Solarisation of Southern Expressway for zero emission:

Somaratna Consultants Chairman/Managing Director K. C. Somaratna speaks of this new proposal to Daily News Business

Question: You are a proponent of fixing solar panels above highways and using that energy to charge batteries of electric cars. You have been working on this concept since 2008. What is the basis of this proposal and how will it benefit the environment?

Answer: I will explain the concept using the southern expressway. If you take the southern expressway and assume it to be 20 metres. wide and 125 kms long we have eliminated 250 hectares of vegetation. This amount of vegetation would have absorbed about 1250 mt of CO2 and 150GWhrs of solar energy per year. So building the highway itself would have contributed to global warming by not absorbing 1250mt of CO2 per year and allowing an additional 150 GWhrs of solar energy per year to warm the environment.

On the other hand if vehicles on this highway consume 50,000 mt of petrol per year (this is 10 percent of total consumption of Sri Lanka in 2008), this would emit nearly 150,000 mt of greenhouse gas Carbon Dioxide. This petrol consumption would have also let at least 500 GWhrs of heat energy to warm the atmosphere.

If we lay solar panels above and along the highway, and use the energy generated to power electric cars then 150,000 mt/year of CO2 emission would be completely eliminated and 500 GWhrs of heat energy been emitted to warm the atmosphere would also be completely eliminated.

These solar panels would have absorbed at least 400 GWhrs of solar energy (this is nearly three times the solar energy originally absorbed for photosynthesis by the vegetation). So you will see that it attacks the problem of global warming on three frontiers. So in my mind, solarisation of highways is the most viable and beneficial solution to global warming.

Question: This word solarisation is not a word found in any dictionary. What does it mean?

Answer: Yes, it is not a word found in any dictionary; but it is the word I have coined up to express this process of laying solar panels along the highways (it could be either above or on the sides or on the surface itself) and using this solar energy captured to charge batteries of electric cars plying along the highway. It is basically converting the highway to be a source of power using solar energy. I believe it is a nice word and it conveys the meaning well.

Question: But they say that energy from solar panels are more expensive than main grid electricity. How much would it cost?

Answer: You are right. Energy from solar panels is more expensive than main grid electricity. If you look at the Sri Lankan situation, main grid electricity is Rs 14 per kWhr and solar panel electricity is around Rs 60 per kWhr. We need to remember a few things here. Main grid electricity is Rs 14 per kWhr because part of it comes from hydropower. Even in 2008, 40 percent of electric power generated was from hydro power. Thermal power generation would be generally at an efficiency of 40 percent while in the internal combustion engine (ICE) of a car the efficiency is only 20 percent. So in order to get one(1) kWhr energy, in the ICE it burns five (5) kWhrs and the moment this efficiency factor comes in, solar energy becomes competitive with petrol for powering automobiles.

So using solar power for transportation is more profitable than using petrol although it is not profitable for generating main grid electricity

If you look at the Southern Expressway, the total cost of solarisation will be about US$ 1 billion. This includes the structures for the panels, solar panels themselves, charging stations and equipment, swapping mechanisms, recharged battery warehousing and transportation, software for billing.

Question: But from where would that sort of money come? It is a lot of money by any standard.

Answer: I agree. Initially I thought that we would be able to get from the US$ 30 billion that was promised at Copenhagen to help poorer countries. I know we are no longer a poorer country - to meet climate challenges. This could be a model for the future and other countries to follow. As such if this funding becomes available, I believe we should be able to qualify for the same.

On the other hand there may be other sources of funding. It was only recently that ‘Investment Forum for Climate’ met in Philippines to work out funding for projects to protect humanity from climate change.

There are huge amounts of venture capital going into other techniques like algae farms. So once we are prepared to take on the project I am sure funds will come or vice versa. But one thing for sure, this would happen, the latest by mid 2011.

Question: So we invest US$ 1 billion on this project and what would be the returns like. Have you calculated the return on investment?

Answer: My first response to your question is do we look at return on investment, when we build a highway. I don’t think, we go to that extent of quantifying the return from the highway in exact rupees and cents.

Nevertheless we have calculated the revenue that could be earned by selling recharged batteries in a year and it works out to about rupees twelve billion a year if we sell electrical energy equivalent to that of litre of octane 90 petrol at one hundred rupees. On top of that there could be some carbon credit, considerable but not so much from the perspective of this investment. The country would be able to save about rupees six billion at rupees 50 per litre of petrol.

Question: What was the basis for these calculations? What was the price of a solar panel taken into consideration, how many days of sunlight was assumed?

Answer: The price of the solar panel was the price that was quoted for any quantity above 1000 pieces (14W panels) which amounted to around euro 35 per panel.

For the quantities that would be required actual price could be much less.

We assumed there to be 200 days on which sunlight be available. Actually there are different standard values which could be used.

One is assuming total solar energy falling on the area in kWhrs per m2 per day and multiplying by the area, rate efficiency of the panel and number of days or the other one may be multiplying the rating of the panel in Watts by the number of panels, by number of hours in a day with proper sunlight and then by the number of days.

These different ways were used and in fact any figure we came across in literature which could ultimately end up in this computation was used to verify our calculation.

Question: How does this compare with other options being considered as solutions to reduce global warming due to transport. I am sure the well-known Nobel Prize winning IPCC Report would have identified certain solutions.

Answer: Yes, I read the IPCC Report with much enthusiasm and especially the Chapter five on Transport. It provides us with a whole heap of data on greenhouse gas emissions due to transportation, the GHGs emitted till fuel comes to storage tank and then from there to the wheel, the mitigation steps prevalent today and projection of GHG emissions till 2050 taking these mitigation measures into considerations.

Unfortunately, this is one solution which they have not looked at. And none of the solutions they have considered do address global warming on all these three frontiers I mentioned; i.e. reduce emission of greenhouse gases, reduce heat pollution due to exhaust gases, reduce warming of atmosphere due to solar energy falling on the highway.

On the other hand these other solutions - say biofuels - from either cane or cellulose or whatever - need space for cultivation, if it is going to be in adequate quantities; you need to transport the fuel to the highway.

In fact according to IPCC Report the greenhouse gas emission during tank-to-wheel phase for ethanol from sugar just balances the greenhouse gas absorption during well-to-tank phase; leaving no benefit to compensate for the impact of loss of vegetation for growing the plants.

It is for these reasons - commercially viable, technically feasible, environmentally least damaging, globally equitable and addressing the global warming issue on three frontiers - that we say that this is the most viable and the fastest solution to global warming.

President Mahinda Rajapaksa’s expectation that Sri Lanka should become a hub for power and energy and knowledge during this decade would become a reality if we could practise this concept and show the world our contribution towards solving the most pressing problem of humanity or all living beings today - the problem of global warming.