Why Weather Matters for Solar Power Plants and Utilities?27 Oct , 2011 | 2
Solar Power Plants are growing at a tremendous rate in the Southwestern US as there continues to be a strong renewable push. With all these solar power plants popping up, it begs the questions…why are utilities hiring solar meteorologists? Why does weather matter for Solar Power Plants? (Also see why weather matters for Wind Farms)
Let me explain by giving you an example.
Let’s say a solar developer has built a solar plant just outside LA, but still in the LADWP (utility) territory. The solar plant wants to sell the energy it generates to LADWP and sign a long term contract with the utility.
LADWP and the solar developer would then enter into a PPA (Power purchase agreement). In the power purchase agreement, the solar plant may say, I promise to deliver X megawatts of power each hour to LADWP for X price. The utility, LADWP, also benefits from this agreement because they are buying from a renewable energy source and the state is required to meet 33% renewable by 2020.
Cool, so the above contract is signed (with hundreds more provisions) and both parties are in agreement. And now it’s the utilities job to deliver the “promised” energy from the solar plant each hour to the grid.
So let’s say the solar power plant is getting sunny weather from 6am-1pm and it’s delivering the megawatts to the utility as promised. Now all of a sudden at 2pm a puffy cumulus cloud makes its way overhead casting a shadow on the solar panels.
Guess what!!? If the cumulus cloud casts a big enough shadow, the solar plant has a major reduction in output…possibly up to 75% for that hour. The utility is now forced to scramble to buy power (possibly at a higher price) from another power provider or marketer to make sure the energy is supplied to the grid as scheduled. The solar plant also loses money on that output! However, if the solar power plant has a big enough real time trading team, they could buy the power from another power provider themselves and uphold the contract.
If only there was someone to tell the utility (or the solar plant operator) when the puffy cumulus cloud would have been overhead in advance. That’s where solar energy meteorologists come in!
Bottom line, the more sun that shines on the solar plant’s panels, the more output the panels have, and the more money the solar plant collects. In turn, the utility receives this output from a “renewable” energy source which gives the utility “credit” towards the state’s 33% renewable goal. A win-win combination!
In my next series of posts on solar energy, I’ll go into more detail about what solar energy meteorologists do specifically and how to break into this amazing and exploding space!