Is it possible to power the world with renewable energy?

Over the last few years, numerous groups have popped up who claim to care about climate change and hold protests with the goal of getting their governments to use more renewable energy. Climate change has been one of the most hotly debated topics of recent times and it would be hard to find people who wouldn’t agree that we need to use more renewable energy than fossil fuels, but is it even possible to make this change with our current level of technology and could a country such as the UK even be able to do this?

The solar problem

Solar energy works by converting sunlight into electricity using photovoltaic cells. It is the cleanest form of renewable energy because it doesn’t require the blocking off of river systems or having huge wind turbines ruining people’s views. It also requires the least amount of maintenance since nothing within a solar system is actually “moving” so doesn’t need to use grease like on a turbine axle. The use of solar energy has been increasing rapidly over the last few years and more and more solar farms are springing up all over the place, but is it enough and will it ever be enough?

The short answer is no, not with our current level of solar technology.

There are three main problems when it comes to using solar energy to power everything, which is space, production, and power storage. All are major concerns especially when it comes to placing them in highly built-up areas such as around a city. For example, a solar farm spread across one square kilometer of land will produce between 150 and 250 Mega-watt hours of electricity each year, depending on several factors. but here’s where it gets tricky. Elon Musk claimed that 10,000 square miles of panels would be needed to power the entire United States, but that’s only in terms of the amount of power produced, and storing it is another problem.

The largest energy storage capability we have in the world is the Moss Landing energy storage facility in California, which can hold 750 Megawatts / 3000 MwHs of electricity. The city of New York can use as much as 10,000 Megawatts daily during the summer months, which means the most powerful and high-capacity energy storage device ever built on earth would be able to power the city for about one and a half hours. it also takes days to charge up from empty to full and also comes with some pretty big safety risks, such as the several fires it has experienced there.

The next major problem would be production, and not just in the cost which would be hundreds of billions of dollars, but also in the raw materials themselves which are already in short supply. Boron and Phosperus are common materials needed to make the silicon-based solar panels we use, and both are expensive and simply don’t exist in the amount we would need them, especially when it comes to powering the whole world.

But this is only with our current level of technology and doesn’t account for the rapidly advancing rates at which solar panels can produce. Currently, solar panels will only convert about 25% of the sunlight that hits them into usable electricity, but this is a massive step up from when they were first introduced at an efficiency of 5%.

In years to come, we will have panels that are close to 100% efficiency, but the closest we have at the moment is just under 50%, these are prototype panels used by organizations like NASA, and they are insanely expensive. In the future of solar panels and energy storage, it will be possible to power the entire world using nothing but the sun, but we are currently decades away from achieving this level of technology, production, and distribution to make it work.

What about other sources of renewable energy?

At the moment we have two alternatives, which are water and wind power. Both produce energy from the turning of an alternator, which is done by moving the turbine that’s connected to it using the wind or water pressure. But as with solar, both of these have some huge disadvantages.

Wind turbines share the same problems as solar energy does, which are cost, energy storage, and the fact they can only work when there’s wind. The other main problem with wind turbines is they are typically very tall, with some of the biggest ones that produce around 2MW being close to 100 meters tall, with rotor dimensions about 25% smaller than this. There are only certain places they can be placed and usually have to go on the tops of hill ranges and elevated positions, which make them visible for miles.

No matter where a wind farm is proposed to be built, there are always people who complain to their local authorities, and some of these complaints take the form of protests and potential legal actions. It is understandable to not want to have your view ruined, but if we want to use more renewable energy we have to put them somewhere. Sea-based wind turbines share the same problem with complaints unless they are placed miles away from the shore, which makes them even more expensive and difficult to maintain.

As with solar energy, wind turbines are making huge advancements and new types are being introduced, such as the vertical axis wind turbine which can work at maximum efficiency, regardless of the direction of the wind and can also be much smaller, but again, we have a long way to go before they reach the levels we need them to, and we also can’t control the wind.

But what about water energy, surely that’s the best one?

Yes, it is, depending on how much you care about the ecosystem. Water is the only non-intermittent form of energy production and doesn’t have to wait until the sun comes out or it’s windy, but it does make a mess of the local wildlife. Hydroelectric dams are an excellent way of storing energy and slowly releasing it to produce a constant flow of electricity, and they are usually big enough to hold enough water to produce power until they can be topped up again from the next rainfall. All this holding back of water that would otherwise naturally flow means that it not only affects the local plants and animals but also starves the ground of its natural water tables and reduces the efficiency of crop growth all along the river it flows into.

The effect it has on local farmland isn’t always a factor, as many dams can be built in remote areas or closer to the sea, there isn’t any farmland to affect, but they always take a toll on the local wildlife.

The other main problem is that you can’t move rivers or control where it rains. A large dam would have to be built on an elevated lake that gets topped up by either streams flowing into it or enough rainfall regularly. The other option, and the one that’s used more often, is to find a steep valley that has a river flowing through it with enough water to power a decent-sized turbine. The valley would be walled up and cause the valley to flood, being released gradually through the dam’s turbine, but locations like this can’t be built or moved, and normally face the same opposition in the form of complaints that wind turbines do.

So what are the other options for renewable energy, there must be something else right?

Sorry to rain on your homestead but I’m afraid not, at least not at the moment. There are other forms of renewable energy such as wave and tidal power, but these are further off in terms of technology and have more problems than the other three methods combined. At our current level of not only our technology but also our ability to produce and pay for things, we are a long way from being able to power the world on renewables alone.

The main problem is energy storage

We are currently reaching our capacity of what we can do with lithium-based batteries, which are the most effective and commercially viable type of battery we have. Their capacity is now only able to be increased by their size, and having batteries the size of buildings is asking for something to go wrong. If you’ve ever seen a phone battery explode then imagine this on a scale about a million times bigger, and having several of them for each city in your country.

Not only do the safety concerns put people off doing this, but they also have the same production problems.

As with the Moss Landing energy storage facility in California, in 2020 it cost $350 to store one kWh of electricity, which would power the average TV for about 10 hours. Compared to a standard Kilowatt cost per hour of about 30 cents from a normal power plant. One of the most common questions asked of eco-protesters is how we store the energy created from sources that only produce electricity when there’s sun and wind, and the answer is always “I don’t know”. Well neither does anyone else, and it seems that with the level of technology we have, and are able to produce in the near future, there isn’t going to be an answer to that question, at least not a realistic one.