12.06.15
Coal-Fired Plants can be Re-Powered Today with Stored Energy from Wind and Solar
There is a consensus in many countries that burning coal to generate electricity is something that needs to be phased out as quickly as possible. The Clean Power Plan in the U.S. has that as one of its most likely outcomes and there have been explicit commitments to retire coal-fired generation plants by governments all over the world.
When considering the options for replacing the electricity generated by coal-fired plants there are two characteristics of these plants that need to be considered. The first is that coal is the cheapest and most abundant non-renewable fuel available. The second is that coal-fired plants are very reliable – more reliable even than natural gas-fired plants because they can stockpile fuel on site so that they are not subject to pipeline congestion problems. And getting approval to build new pipelines is not easy these days.
One of the strategies for replacement of coal-fired generation is the development of more wind and solar power. This approach is not without its problems because of the inability to store energy from these sources which are often not available during peak demand times of the day. Matching the 24×365 reliability of coal-fired plants using renewables would be very challenging.
When you think about it the only thing wrong with coal-fired plants is the fact they burn coal to produce the steam used to drive turbines. If a renewable source of heat could be supplied to these plants they could continue providing reliable power and the negative aspects of burning coal would be eliminated.
In jurisdictions where renewable energy sources have been developed extensively the disconnect between electricity production and system load is starting to become problematic. For example, on many circuits on Oahu the amount of electricity generated by roof-top solar panels actually exceeds system demand mid-day some days. Although there is plenty of potential to expand solar power in Hawaii from a resource standpoint it will not be possible without the ability to time-shift production to match demand through the use of energy storage. As a result solar panel permits have been falling for a number of years and hit a 5 year low of 100 permits for the month of January, 2017.
In Denmark, where the nameplate capacity of wind turbines is approximately 1/3 of total generation capacity in the country, wind generation frequently exceeds domestic demand which requires the export of the excess to neighbouring countries. Obviously if all of Denmark’s neighbours also developed a similar amount of wind capacity there would be nowhere to export the electricity to. Texas and parts of the American Mid-West are facing similar issues.
So we are faced with two different problems;
- The need to stop burning coal to generate electricity
- The need to store excess electricity generated from wind and solar
Fortunately, there is a combination of field-proven technologies available today that can solve both problems. I will refer to this combination of technologies as “Thermelectric Power”.
Thermelectric Power provides a large rapid response load which can be used to stabilize the grid when there are variations in renewable energy generation. It also stores renewable energy by converting it to thermal energy.
The mechanism for storing the energy is molten salt
@enrgy_manifesto
