What are renewables?
A renewable energy source is an energy source that doesn’t run out. Fossil fuels, like coal, oil and gas, are finite, meaning that we will run out of them eventually. When fossil fuels are burnt to create energy, they produce greenhouse gases. Renewable sources of energy, however, are more sustainable and environmentally friendly. Solar, wind, hydro, tidal, geothermal, wave and biomass are the most common types of renewable energy discussed. Solar and wind farms have become cheaper to install than gas and coal plants across much of the world.
But could we generate all our power with them?
Yes, according to LUT University and Energy Watch Group. They predict we could transition to 100% renewables (for heat, power, transport and water sanitation) by 2050. It would just take political will but would make economic sense. According to their models, we would need 4-5x the electricity generated in 2015 to cope with future demand, as most energy demands would be electrified. Solar and wind would make up around 88-96% of these renewable sources. According to some studies, the world would only need to exploit 1% of its potential renewable resources to replace all fossil fuel usage.
Already, countries are depending considerably on renewables. Scotland is an example of one country already meeting almost all of its electricity demands with renewable sources – 97.4% of demand was met this way in 2020. Iceland produces around 77% of its total energy from renewables.
Electricity storage – matching supply and demand
The issue with renewables is that most of these greener energy sources are dependent on things humans can’t control – like the weather or tides. With fossil fuels, it’s easy for us to create energy to match peaks in demand. This is more difficult with renewable sources that are controlled by weather conditions… although biomass and pumped-hydro can act in similar ways to fossil fuels in this respect, by helping to fill gaps in supply.
In order to provide all of our electricity with renewables, a mix of renewable sources is required – through a smart grid that reacts to our needs. Smart meters are one way of aiding us the move towards making our grids smarter. Hydrogen storage, battery storage, over-producing energy during peaks and potentially even storage in electric cars are all ways we can help deal with the differences in supply and demand. And like most things in this area, the technology keeps improving, prices keep dropping and efficiency keeps improving.
Setting the record straight: renewables are not worse for the environment
An argument often used against renewables is that their construction is devastating for the environment. Although construction will have an environmental footprint, so does the construction of fossil fuel plants and extraction of these resources. Renewables can have various negative environmental impacts, especially if they are not sited correctly, as can coal or gas plants. However, renewables still have clear environmental benefits over fossil fuels – their electricity production is effectively greenhouse gas free. And again, as our knowledge improves, the environmental effects of construction can be minimised.
Although constructing renewables can produce a lot of CO2, far smaller quantities are produced in their lifetime than from fossil fuel sources. Renewables are thought to produce 50g or less of CO2/kWh over their lifetime – coal sources produce around 1000g CO2/kWh or 475g CO2/kWh for gas.
There is increased confidence that renewables could provide the world with all our energy demands. In order to do this, a mix of energy sources is required. As with most green technologies, improvements in efficiency, environmental impact and cost are just likely to keep coming. We just need governments to move away from those fossil fuels they’re used to depending on…
- EDF Energy – Renewable energy – https://www.edfenergy.com/for-home/energywise/renewable-energy-sources
- Bloomberg – What’s behind the world’s biggest climate victory? Capitalism – https://www.bloomberg.com/graphics/2019-can-renewable-energy-power-the-world/
- Energy Watch Group – New study: global energy system based on 100% renewable energy – http://www.energywatchgroup.org/new-study-global-energy-system-based-100-renewable-energy/
- Green America – Could the world be powered fully by renewable sources? – https://www.greenamerica.org/green-economy-work/could-world-be-powered-fully-renewable-sources
- BBC – Renewables met 97% of Scotland’s electricity demand in 2020 – https://www.bbc.co.uk/news/uk-scotland-56530424
- Wharton University of Pennsylvania – Can the world run on renewable energy? – https://knowledge.wharton.upenn.edu/article/can-the-world-run-on-renewable-energy/
- World Resources Institute – Setting the record straight about renewable energy – https://www.wri.org/insights/setting-record-straight-about-renewable-energy
- Forbes – How renewables could kill off fossil fuel electricity by 2035: new report – https://www.forbes.com/sites/davidrvetter/2021/04/26/how-renewables-could-kill-off-fossil-fuel-electricity-by-2035-new-report/
- The World Bank – Renewable energy consumption (% of total final energy consumption) – https://data.worldbank.org/indicator/EG.FEC.RNEW.ZS?most_recent_value_desc=true