Scotland recently experienced a day of gusts so strong the winds met all of the needs of its power grids for the day.
Yet, the unusual weather highlights the variable nature of wind power and the difficulties it can cause for power grid operators. The IEA in its Next Generation Wind and Solar Power gives some idea of the technical problems that will only grow as the share of electricity provided by wind and solar grows and integration becomes a critical issue.
Wind and solar power use is set to expand rapidly over the next 25 years, according to Bloomberg New Energy Finance (BNEF).
Falling costs of hardware, concern over emissions of greenhouse gases, and a desire for energy security have all but assured the rise of the variable power sources; however, they are not without problems. Higher costs of backup power plants, the disruption of communities with economies tied to conventional fuels, and the need for an upgrade to an outdated, inflexible grid infrastructure all come to mind.
Power grids will need to take on an unprecedented level of flexibility to deal with an influx of renewable energy capacity. That flexibility will have to come from a variety of technological and operational innovations such as renewable energy forecasting, careful scheduling, enhanced electricity storage options, and a more robust, farther reaching transmission infrastructure.
As the grid stands today, it simply isn’t ready.
Forecasting and scheduling are better than ever with advances in computing, but batteries are still relatively expensive and the grid is woefully outdated. With 70% of high-voltage transmission lines and power transformers over 25 years old and the majority of our grid was built more than 30 years ago. The grid is too poorly equipped to manage the steadily increasing demand from electric cars, let alone a substantial rise in intermittent supply.
Adding to the confusion is distributed generation. Though it would seem that making and using power on site would eliminate the problem of infrastructure, unless the user is completely independent from the grid – unlikely for most unless energy storage options improve significantly – power companies will have to understand the needs of a new breed of consumer. A home with solar panels would still need some infrastructure and a back up power supply. Also, the decreased system load would only benefit the power companies so long as the lost revenue outweighs the cost of upgrading the grid to handle excess demand.
Mankind’s appetite for electricity is only growing so these problems are best addressed sooner rather than later.