The alternative energy industries have been struggling to define how solar and wind power sources can become reliable sources of power in the context of the mainstream utility grid. Hopefully everyone knows that solar and wind are energy sources that are only present when there is daylight and wind. Kind of obvious, but the practical outworking is definitely not obvious or easy to deal with.
Solar power peaks in the early afternoon in most locations around the US. This is great for big cities with big air conditioning loads that come on in the late afternoon. The problem is partly that there is a 2-3 hour gap between peak solar and peak demand, when everyone is coming home from work. This demand is mostly in the summer, and only for a few hours a day, so using solar to reduce peak demand is a potential strategy, but only if it’s really inexpensive. Preferable half what it is today. That’s not great news for the solar industry.
Wind, well, it’s only there when it’s blowing. Given the limitations of the horizontal wind turbines that are currently being produced, wind is an intermittent source. What’s really scary is the extremely high power units that are being engineered and the complexity of bringing this power on to the grid. There have been some recent problems with large farms and the ability of the grid management to accommodate the intermittent loads popping up and surge currents causing switching systems to shut down. Also not great news for the industry.
Both wind and solar would benefit from a good storage solution. Intermittent sources of energy can be stored and used as needed with relatively steady output, unlike the sources. Easy to manage, and in the case of battery storage, no moving parts. Cool.
But battery storage is really expensive. Consider the Tesla sedan with a $30,000 battery pack. Big bucks, especially when a wind farm might require 5 megawatts of battery storage to store and level the output. Even with increased manufacturing capacity and forecasting very aggressive cost reductions, it’s a huge price tag added to the already expensive equipment. The biggest battery companies in the industry have tried and failed to scale up and reduce cost sufficiently to impact their market. A123, once the leader in 2MW battery trailers, closed up and was sold to a Chinese investor. Sad.
There are some great technologies in development that I expect will cure the battery situation in about 3-5 years. But that will not help us solve today’s storage problems.