Hawaii has been called a “postcard from the future” due to the high levels of renewable energy being deployed and technical work that is being done to accommodate this. But even for Hawaii the amount of solar that has been put online in the island of Kaua’i is impressive, as are the technical challenges being faced.
With the recent addition of a 12 MW-AC solar PV and integrated battery storage project, Kaua’i is now getting an estimated 17.5% of its annual electricity from solar PV – roughly double that of Italy, which meets the highest portion of electricity demand with PV of any nation in the world.
When the island’s biomass and hydro are factored in, Kaua’i met an estimated 38% of its electricity with renewables in 2015, more than Germany or California. And this is only the beginning. SolarCity is planning another 12 MW-AC PV plant with integrated storage, and the island expects to meet 25% of annual demand with PV in 2018.
You would think with these kinds of impressive numbers that Kaua’i is an easy place to integrate wind and solar. It isn’t. In fact, Kaua’i faces some particular technical challenges which places like Germany and California do not have to deal with.
Kaua’i is an island less than one hundred miles across at the longest point, with a population of only 66,000. It is also more than one hundred miles from Oahu, and there is no electrical interconnection with the rest of Hawaii, making it an island in the both the geographic and electrical sense of the word. This means that like many other islands, Kaua’i cannot export power in times of oversupply or import power when wind and solar output is low.
Also, the degree of variability in the output of an individual solar project is overcome when PV installations are spread over large geographic areas. Kaua’i and other small islands face more intense variability from PV output and integration of high levels of PV and wind is particularly difficult.
Furthermore, as an island with no factories, little daytime air conditioning use and a tourist economy, Kaua’i’s peak electricity demand is after the sun goes down – which is the opposite of most regions, and far from conducive to integrating large amounts of solar.
Finally, due to an issue with endangered seabirds, Kaua’i has no wind turbines. I personally find this odd, and wonder if Kaua’i has also banned power lines, cars and house cats, given that each of these kills multiple orders of magnitude more birds annually than wind turbines. But for whatever reason, there is no wind power. This too makes a transition to renewable energy more challenging, as in many places wind provides more power overnight, and can help to balance out PV on the grid.
This fall I had the opportunity to talk with Kaua’i Island Utility Cooperative (KIUC) Spokesperson Jim Kelly about how the island is tackling all of this. It was a fascinating conversation, and I encourage anyone who is curious about integrating high levels of variable renewable energy to read the interview.
There are two key takeaways. First: As Kaua’i is proving, any alleged “limits” to levels of wind and solar integration are a joke when energy storage (including pumped hydro) is considered. Second: if Kaua’i can do this, there is no excuse for other regions, where the integration of high levels of wind and solar does not face these sorts of technical challenges and unfavorable conditions.
Interview with Jim Kelley, KIUC (via pv magazine)