Is 100% Renewable Energy Possible?
Since the start of the sustainability and climate change debate, a pretty big question has cropped up time and time again: can we move to a 100% renewably-powered world? Is it possible that everything we do that requires some kind of energy, from keeping the lights on to running our cars to watching Netflix, let alone industry and commerce more broadly, can be powered using renewable energy?
This debate has been used time and time again as an argument (if not THE argument) against growing renewable energy development by people opposed to a more sustainable energy system. “What happens if the wind stops blowing!”, “What happens if the sun stops shining!”, and so on, are trotted out as insurmountable arguments against renewable electricity. Renewable heat, for some reason, doesn’t seem to encounter such stiff resistance, probably (let’s face it) because when people are talking about energy, more often than not they’re actually talking about electricity. We’ll get to talking about the heat a bit later, but let’s focus on electricity for the moment. There are a few main factors that we need to examine to see whether 100% renewable electricity is really possible: where you are in the world, what kind of demand exists in the local electricity system, and the scale of energy user you are (IE whether we’re talking about companies, countries, or individuals).
So let’s look at the geography first, because, short of some serious geo-engineering, that’s not going to change for the foreseeable future. There are a couple of major factors that affect whether the transition to 100% renewable electricity is going to be possible on a nation-state scale: renewable energy resources in the country in question, and the capacity for investment, IE how much money can the country throw at the problem. For countries like the United Kingdom, for example, our capacity for expenditure is relatively high: we are a developed world nation with strong government revenues, but the structure of our electricity sector (with privatised power producers and distributors) may mean it’s difficult for the government to incentivise companies to invest in renewable electricity production. This is all as maybe: what we’re really examining here is could it be POSSIBLE. The answer to this is yes, absolutely, the UK has huge amounts of some renewable energy sources, such as wind energy, and while we’re not traditionally the sunniest country (understatement of the century) solar is still very viable in the UK, particularly at an individual scale. For other countries, such as, say, Uganda in Africa, wind resources are fairly low, but the solar resource is very good indeed, and other renewable electricity sources such as hydropower are pretty strong as well.
The lesson from all this is, regardless of where you are in the world, there’s a renewable electricity source that can be used, given the investment to make it work. So let’s drill down a bit: what about if you’re a large company, or if you’re an individual looking to make sure that your electricity is renewable, even if the country’s isn’t quite yet? Is 100% renewable electricity possible at that scale? Again, the answer is absolutely. There are a number of barriers that need to be addressed at a government level for it to be completely feasible without limitations for companies, such as financial assistance to get over the capital expenditure hump of installing new renewable electricity generation, but in terms of overall possibility? Absolutely. The situation is brighter for individuals: capital expenditure for offsetting an individual’s electricity consumption is significantly lower, although the drop-off in government renewable electricity incentives has hurt the sector somewhat. But in terms of whether 100% renewable electricity is possible, there are people out there today across the world living their lives on 100% renewably-source electricity. So yes, definitely.
So turning our attention to renewable heat, this is a little more complex. At an individual scale, the problem is not so bad, and there are a plethora of technologies available in the form of heat pumps, solar water heating and so on, that make renewable heat easy to access. The problem comes with large industrial heat applications, such as foundries. Renewable heat source technologies to date have been very good at so-called “low-temperature heat”, the definition of which can range from about 50°C to about 200°C. High-temperature industrial heat, however, is harder to get to with renewable sources. However, harder to get to does not mean impossible! Solar collector towers, such as the ones used in Spain or Nevada for electricity generation, run at some fairly stupendous temperatures. Using this type of technology for heat rather than energy storage could be one route to high-temperature industrial heat applications on a 100% renewable basis.
There are a couple more things that are worth mentioning in brief: battery storage and electricity grid interconnection. Battery storage has been seen as the great hope of 100% renewable electricity, and rightly so, there’s huge potential there. At the moment, the technology is still fairly expensive, and the debates around batteries at a grid, company and individual scale is a blog topic in itself! Grid interconnection is being used today to help achieve higher levels of renewable electricity use in national grids. Is the wind blowing in Denmark, too much for them to use? Brilliant, send it to Norway, store it in their pumped hydroelectric storage reservoirs. The wind stops blowing, let the water down, send it back! This is just one example: if the wind’s blowing in Scotland, or the sun’s shining in Romania, why not send the power to Germany where it’s still and cloudy?
So to summarise: is 100% renewable energy possible? Absolutely, but possibly not yet. There need to be a few changes in how we, as global citizens, act and interact, but the technical potential, and indeed the social potential, is most definitely there.