Friday, August 28, 2009

Solar-Powered Oil.

This is a nifty idea: an oil field which employs solar energy to generate steam for enhanced extraction technologies. This particular innovation is due to Brightsource Energy who are using a 29 MW solar thermal power plant at a Chevron oil field based in Coalinga, California. The method of CTSP (Concentrated Thermal Solar Power), sometimes abbreviated further to CSP, uses an array of mirrors to focus sunlight onto a central boiler and so generates steam which can be employed to drive a steam turbine and generate electricity in the usual manner. This is a more efficient process currently than photovoltaic technology, but in the present example, rather than the steam being fed into a turbine, it is to be pumped down the oil-wells to help fluidise the oil.

The oil is thick and sticky at normal temperatures but when heated it flows more easily and can be pumped-out more readily. Oil companies often use steam for this purpose of so called enhanced extraction, but normally it is produced using fossil fuels such as gas, for example in the Fresno and Kern counties of California where the oil is particularly "heavy and gooey" to quote from the article cited below. Since this region also collects some of the most intense sunlight in the state, a happy marriage is to use some of it to get the oil out. Indeed, there are a number of other CSPs planned to be built in this region.

Brightsource has investments from Chevron, BP and the Norwegian Statoil Hydro (from a merger of Statoil and Norsk Hydro) and it has signed contracts to provide some 2,610 MW of electricity generating capacity from the CSPs. The solar-powered oil scheme is more important in view of the fact that a significant part of the costs of oil extraction relies on the cost of the natural gas. Presently, gas prices are around $3 per million Btus (British Thermal Units) and it is thought that once the price reaches $8.5 per Btu the solar steam system will prove competitive with the gas-fired units. Gas prices will rise as indeed will the price of oil and so in the longer run this could be a lucrative investment. I suppose there is less carbon emissions too, although since oil is being produced which will be burned overall it is not so environmentally friendly.

The rider is that the solar steam plants only work when the sun is shining and hence back-up units will be needed, which still use gas; the perennial problem of most renewable energy sources - that the power supply is not constant, be it solar, wind or wave.

Related Reading.

"A Solar-Powered Oil Field?" By Todd Woody. The New York Times, Green Inc. Energy, the Environment and the BottomLine.


Yorkshireminer said...

This is an old field with a very fat tail been producing for over 100 years now, politically safe no large bribes needed and right in the centre of a large market no transport costs, most likely has a pay back time of less than 5 years a good idea. It also looks as if Chevron expect the price of natural gas to rise in the next few years.

By the way Chris this is a bit of good news I came across a couple of months ago perhaps you missed it.

Professor Chris Rhodes said...

Yes, if they can cut back on the amount of gas they need to use to get the oil out it could cut costs some.

It is a safe one, and probably will be pumping out oil for some decades to come - in the face of so many others that will have dripped-dry by then.

The link is interesting but seems to be about a fairly complex technology, which would still be some way off.



Anonymous said...

Brightsouce’s bright idea.
Routinely now, discussions of solar plants include the caveat that “ steam plants only work when the sun is shining …etc”.
Now in this case I wonder whether a back-up plant is really needed?
Suppose the owners decided to operate the plant during sunlight available hours. At other times the plant would be stopped. Shareholders will be distressed at the loss of income from the none-sunlight periods. On the other hand they will be pleased at the capital saving resulting from the none-necessity of building a back-up plant. They would save on back-up plant operating costs, including fuel and emissions control. The environment would gain.
During non-sunlight periods maintenance would be planned and carried out. Workers would have nicer lives, working when the sun shines (except for the maintenance people who would always be on nights, but hey, no one forced them into that field did they? Presumably they would be better paid than the sunshine boys.)
A profit /loss calculation for the two plant modes (24/24 v daylight only) would be interesting.
Wouldn’t a scheme such as this fit in nicely with your future world view, Chris, of a fuel scarce world, with localised industries?

Professor Chris Rhodes said...

Is this you, Peter? In any case, a very good point. Agreed, IMHO in a resource-scarce world, pulling as much of what remains from the ground as fast as possible is a very short-term and limited strategy.

So, in my lower energy expectation, why not use this method only "when the sun is shining" and forget about using gas etc. to run the plant hell for leather 24/7?!

But as you say, it is all a question of money/greed/capitalism etc. and the shareholders and investors will want their pound of flesh.

As an environmental strategy pure and simple, I agree that it has much to recommend it, especially in a world that has by design or default devolved into using less in the way of oil and all other resources.



brian said...

certainly interesting times coming down the pike, mexico i guess will be the guinea pig for peak oil.also with peak oil comes peak population (without an alternative)and the 2 peaks will not be simultaneous timed. with predictions of a loss of 40% of their revenue, not to mention the costs of now being an importing country, mexico is doomed.other countries will follow.
sorry but somebody has to get the words out:peak population

Professor Chris Rhodes said...

Sadly Brian, I agree with you entirely! Yes there are too many of us using up too much stuff. There's no easy way around that one!

There are measures of energy curbing and so on possible but a painless transition may not probe possible.



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