On Sunday, Scotland produced 106% of its electricity needs -over a 24 hour period – via wind farms. Scotland joins a select group of countries that have had peak moments (or days/months/forever) when their electricity needs comes from non-polluting renewable energy. Iceland runs completely on hydroelectric and geothermal, Costa Rica ran for 75 straight days in 2015, Portugal ran for four days, Denmark generated 140% of their demand, Germany broke 95% for a few moments and there are many other countries with wonderful clean energy achievements. With places like Hawaii aiming for 100%, Rhode Island building its first off shore wind farm and the US Department of energy readying the mainland’s grid to be able to handle 100% – we will see reports like this proliferate in the future.
On a blustery Sunday with hurricane speed winds off the coast, and 60 mile per hour gusts in the highlands – Scotland produced enough electricity in a 24 hour period to meet 106% of the day’s needs. Turbines spread across the land and in the ocean surrounding Scotland provided 39,545 megawatt-hours (MWh) of electricity to the National Grid on Sunday while the country’s total power consumption for homes, business and industry was 37,202 MWh. Scotland’s goal of generating 50% of their annual electricity from renewables is on pace to happen a full year early. Scotland also has a goal of 100% renewable electricity by 2020, but it might only get to 87% per some reports. Still – 87% over the course of a year is a powerful value and will probably mean 100% will arrive before 2025.
Of course, wind energy is only generated when the wind blows. The intermittent nature of wind power means a form of storing this energy must be developed – Scotland is working on this as well. While ideas like the Strathdearn Pumped Hydro scheme are continental scale intellectual exercises at the moment, Scotland’s Cruachan pumped-storage facility is very real and can deliver power from a cold start in two minutes or 30 seconds if the pumps are primed. A recent study was completed looking to double the size of the current plant – ScottishPower would need to invest between US$418 million to $557 million to complete the projected eight- to 10-year endeavor if the UK government approves all aspects of the expansion process.
Pumped storage, moving water from a lower elevation reservoir to a higher elevation and then allowing the gravity to pull the water back down turning a turbine, has already found a significant place across the world with some very large ideas being developed further to compliment renewable juggernaut Germany and broader Europe.
Scotland has also pushed other forms of energy storage (PDF):
There are several islands in Scotland where energy storage is used to facilitate renewables, including Orkney (Li-ion, 2 MW, operational 2013), Isle of Eigg (lead acid, 212 kWh, operational 2008 & flywheels, 200kW, operational 2014), Isle of Gigha (vanadium, 1.25 MWh, est. operational mid 2015), and Unst (hydrogen fuel cell).
The key value in these smaller electro-chemical systems (batteries) is that they allow smoothing of electrical generation across a complex grid – not necessarily large scale storing of it – as the wind does blow quite consistently when the turbines are spread across large areas.