cyprusgrump wrote:supporttheunderdog wrote:kurupetos wrote:What they simply do is to reverse the combustion process (or electrolysis, etc.), and produce (or recover) fuel.
This is possible, but to achieve it you will need an efficient energy source, which in the case of sunlight is not an efficient one.
Sunshine is however free at source. The key point is whether the total cost of the process is more or less than that of producing by other means. an equivalent amount of fuel with the same energy value,.carbon foot print etc.
We've discussed this before...
There is a good article here which describes in detail the problems with using 'free' sunshine as an energy source....
Yes we did and I remain sceptical about they ability of wind anda solar to oust much hydrocarbons use.
What we ned to o is make our buildings more ener gy efficient and reduce consumption by better design and construction to maximise passive and other natural warming and cooling methods, then think about using eg building-basedw solar, including PV to reduce the load on the central generating systems.
One idea floated recently (which was another half baked idea) was to combine solar electricity with pumped storage, but what the academic may not have thought out is that such schemes need a lot more electricity to get the water back in the top lake than it makes as it falls down. The solar capacity would thus need to be enough to fulfil usual daytime needs plus enough to run the pumps fast enough to get the water back up to the top pond. That's without the problems of finding suitable storage locations for the water.
Every form of activity which consumes energy has a down side in terms of use of land and rescources, waste generation, etc.
