terça-feira, dezembro 27, 2016

Verdes ilusões

O esgotamento do nosso modelo energético é a principal causa dos nossos problemas presentes e futuros

Euan Mearns has shown that in Europe, countries that use large amounts of wind and solar tend to have very high residential electricity prices. This comparison strongly suggests that when costs are charged back to consumers, they are very high. (In the US, subsidies tend to be hidden in the tax system instead of raising prices, so the same pattern is not observed.) 
It seems to me that going forward, a completely different approach is needed, if we want to evaluate which energy products should be included in our electricity mix. The low energy prices (for oil, natural gas, coal, and electricity) that we have been experiencing during the last 30 months are a sign that consumers cannot really afford very high electricity prices. Analysts need to be looking at various scenarios to see what changes can be made to try to keep costs within the amounts consumers can actually afford to pay. In fact, it probably would be helpful if building of new generation could be reduced to a minimum and existing generation could be kept operating as long as possible, to keep costs down. 
A Long-Term Role for Solar PV
It appears that our civilization is reaching limits. In fact, it seems likely that our current electric grid will not last many years–probably not as long as people expect solar panels will last. We also know that in past collapses, the only thing that seemed to partially mitigate the situation was radical simplification. For example, China transported goods in animal-powered carts prior to collapse, but changed to transporting goods in wheelbarrows, after it collapsed about the third century A. D.
Building on this idea, the place for intermittent renewables would seem to be off the electric grid. They would likely need to operate in very small networks, probably serving individual homes or businesses. For example, some homeowners might want to set up 12 volt direct current systems, operating a few LED lights and a few specially designed 12 volt direct current appliances. Businesses might want to do more. The problem, of course, comes in maintaining these systems, as batteries degrade and other parts need to be replaced. It would seem that this type of transition could be handled without huge subsidies from governments.
The belief that we can maintain our current electric grid system practically indefinitely, using only wind + solar + hydroelectric + biomass, is almost certainly a pipe dream. 
in EROEI Calculations for Solar PV Are Misleading
Posted on December 21, 2016, by Gail Tverberg

Sem comentários: