Renewables round up
Our latest renewables round shows plenty of new potential, but still some concerns that the overall strategy may not be deliverable.
The case for renewables is set out, with much enthusiasm, in this FoE blog post at Left Foot Forward, “Energy security, jobs and carbon reduction. All in one. And since the sun and the wind will remain free as the technology to harness them improves, the potential for cost reduction is almost limitless. The countries which grasp this the quickest will be the winners in the 21st century, just as those who first piled into coal and steam were in the past.”
If you are sceptical about decentralised power, what about the Saharan sun? Up to 2.5 million British homes could be powered by Tunisian sunshine by 2018 under an £8bn plan to build a giant solar farm in the Sahara desert and ship the electricity to Europe through a 450km (280 miles) submarine cable. Solar power could outstrip fossil fuels, other renewables and nuclear to be the biggest source of electricity by mid-century, according to the International Energy Agency.
Germany is the new model for the renewables industry. They are well on the way towards having a predominantly green electricity supply. The transition from nuclear and fossil fuel electricity to using renewables is happening faster than anyone had anticipated. However, it is hugely expensive largely because the weather is notoriously unreliable and variable. So a secure system needs more renewable capacity and also more reserve capacity from conventional power plants (mainly fuelled by natural gas) to make sure it can always meet demand. As the chart below indicates, installed renewable capacity in 2050 is expected to be 180GW, which is roughly twice maximum demand.
One indicator is that electricity tariffs have almost doubled since 2000. Meanwhile CO2 emissions have not decreased, but actually increased over the last few years because coal-fired power has been on the rise while nuclear wanes. German technology might not hack it this time.
Can renewables really provide all of Scotland’s needs?
Scottish ministers have approved four major offshore wind farms that it is claimed could generate enough electricity for more than half of the homes in Scotland. On windy days of course. This seems fine on a day like today, but its not always like that. The Longannet announcement and problems at Hunterston, highlight some security of supply challenges. Others argue that the UK government is strangling offshore wind through the Electricity Market Reform plans. UK government estimates of expected offshore wind generation by 2020 have gone from 18 GW in 2012 down to just 10 GW.
Marine renewables have had something of a boost with the announcement that the developers of a planned tidal energy scheme in the Pentland Firth have signed a 10-year Power Purchase Agreement (PPA) with energy firm SmartestEnergy. Under the first phase of the project, four 1.5MW turbines will be installed on the seabed. MeyGen said eventually the scheme could have up to 269 turbines and it plans to start installing devices over the next two years.
Lets also not forget demand reduction. The Energy Saving Trust reminds us that households could save £356 million by making simple changes to their energy use. Around 594,000 tonnes of carbon emissions could be cut by minor improvements such as installing solar panels, switching to LED bulbs and switching appliances off rather than on standby.
So, plenty of potential projects, but questions of actual delivery and cost remain. We will also still need conventional power sources to balance the system. The phrase, all our eggs in one basket, still springs to mind.
- Posted in: Renewable energy