by John Brian Shannon | May 2, 2013
Hybrid power plants combine daytime solar power with nighttime wind power or biomass energy to add reliable power to the grid every day of the year
One option for renewable energy producers that has been rarely utilized is the installation of both wind power and solar power plants together at the same location — which results in doubling the amount of electricity produced — vs. solar (alone) or wind (alone) at power plant sites.
Prior to a study done by Reiner Lemoine Institut and Solarpraxis AG it was incorrectly thought that the huge wind turbine towers would cast long shadows over the solar panel array thereby reducing their efficiency.
But it turns out that when solar and wind power generation are combined on the same site, such hybrid power plants complement each other better than had been imagined. Approximately twice the power generation is available from any such hybrid power plant site, when compared to wind only, or solar only.
The landmark study took into account sunlight loss (shading) which would occur in a carefully designed hybrid power plant. Energy losses were less than 2 percent of total output.
This is a lower energy loss percentage than compared to conventional power plant energy such as coal — where up to 10 percent of the coal can be lost during transport and storage.
A major benefit of renewable energy hybrid power plants is that due to the intermittency of both wind and solar, is that they cancel out the others’ weaknesses.
Wind usually peaks at night, during cooler days and in the colder seasons of the year — while solar produces power during the daylight hours, the warmer parts of the day and most especially during the summer months when the Sun is directly over the solar panel array.
Until now, it was thought that the shadows cast on solar plants by wind turbines led to high yield losses. The study shows, however, that these shading losses are much lower than expected, provided the hybrid power plant is well designed. Initial requests to create yield reports as well as technical and economic system planning have given us cause to hope that the more efficient utilization of space and infrastructure created by hybrid power plants has excellent prospects for the future.” — Alexander Woitas, Head of the Engineering Department at Solarpraxis AG
Many utility companies are already operating solar and wind hybrid power plants and are planning hybrid power plants over the next few years.
The U.S. state of Massachusetts has easily surpassed its previous goal of 250 megawatts (MW) of solar energy by 2017 and is planning to increase that goal to 1,600 MW (1.6 GW) of solar energy by 2017.
Boulder City, Nevada, is likewise adding wind turbines to their huge and ongoing solar power plant installations — so they can sell solar electricity to nearby cities and towns during the day, while adding the ability to sell during the night.
Energy Services (WGES) in Washington, D.C., buys wind power from a nearby producer and solar power from another nearby producer, and sells that electricity to residents, businesses, industry and the government throughout the northeast , including D.C.
I recently interviewed Mr., the President of WGES, and speaking on the intermittency of wind power (and similar applies to solar power) he said that it is quite normal for power producers to add different kinds of power at different times of the day.
The power grid operates with a variety of power plants constantly coming on line, going off line, and ramping production up and down to meet the varying demand for electricity over the course of the day and over the course of the year.
There are always power plants idle and ready to generate more as part of the overall plan to assure reliable power.
So, nothing special is needed to back up wind power. Load merely shifts to other power plants when the wind isn’t blowing.
When the wind is blowing, other power plants, many of which burn fossil fuels like coal, ramp their operation down.” – WGES President, Harry Warren
Combining wind and solar power plants (hybrid power plants) can add power 24/7/365 to electrical grids, lower CO2 emissions, and help to lower the cost of electricity to consumers.
- Solar / Wind Hybrid Power Plants Approximately Twice As Efficient (CleanTechnica)
- Solar projects take home of Hoover Dam back to future (Las Vegas Review-Journal)