What happens if the world runs out of fossil fuels? No more cars, no electricity, no air conditioning. As soon as the last batteries are exhausted, we will return to the Middle Ages. We can not allow this.
Energy is expensive, and as we continue to deplete the Earth with our oil, the price of energy will only rise. — that is, if we can’t find another way to generate electricity. When fuel is so important become commonplace, that’s when you’ll know the problem is real.
Seriously, we could run out of fossil fuels by 2060.
Solar energy is our hope but the development of this technology over the past few decades has been weak. How long before solar energy lives up to its promises? What’s taking so long? Will the energy revolution come in time?
The world needs solar power…
To be fair, solar power is not the only alternative to fossil fuels. Brilliant minds around the world are exploring many other possibilities, and while they all show varying amounts of potential, they all have serious flaws.
For example, wind energy . The wind is everywhere and full of energy potential. It’s green, has low pollutant emissions, and is relatively efficient when it comes to space requirements.
Unfortunately, the wind is unpredictable and often accompanied by periodic surges, which is not very useful if we cannot provide long-term storage of the energy produced. Not to mention, wind turbines can be very loud and dangerous to maintain.
In addition, large wind farms can have a direct impact on local weather (affecting air circulation) and local wildlife (turbines that kill birds and bats). This may be mitigated by the development of bladeless wind turbines, but it is too early to tell.
hydroelectric power plant is another source of fuel that has proven to be effective but problematic. Hydroelectric dams are destructive to aquatic ecosystems, creating stagnant pools, disrupting migratory habits and directly killing many fish species.
Other types of alternative energy, including biofuels and hydrogen have difficulty in overcoming the most basic problems: their production requires more energy than the energy offered at consumption .
Another worthy option is nuclear energy, which is much more environmentally friendly than fossil fuels per unit of production. However, waste disposal remains a problem and there is still a problem with the final fuel. Nuclear power may buy us time, but it is not a permanent solution.
Which leaves us solar energy only as the only likely long-term solution.
… But there are many obstacles
We briefly looked at why solar energy did not take before, but let’s look at it in more detail. If the sun is our supposed savior from fossil fuel depletion, why the hell stop the solar revolution?
It turns out that we have several obstacles to jump over.
First of all, as wind energy, solar power is intermittent . It is well known that solar cells generate energy only when the sun shines on them. This simple problem makes solar cells completely inefficient for large parts of the world.
Take a city like Seattle or London. These are areas where more rain falls than sunshine during the year. To power these cities with solar energy alone, each day’s solar energy must generate at least two days of electricity. Solar technologies are not far from this possibility now.
What about the Amazon rainforest? This is 2.1 million square miles of land that is unable to use the sun’s rays for electricity. What about countries beyond the Arctic Circle? These places can see the sun for six consecutive months and then darkness for the next six months. They will only have electricity for six months. The pooling of energy between different areas also presents a problem because the loss of energy along long transmission lines becomes excessive. We could fix this with room temperature superconductors, but that technology is still a long way off.
Which brings us to the next big problem: solar energy storage . If solar energy production is only available at certain times of the day in certain regions of the world, the obvious answer is to harvest that energy and store it for later. Unfortunately, this much easier said than done.
The problem is that cheap batteries have durability or reliability issues, and quality batteries are prohibitively expensive to manufacture. In 2013, large-scale lithium-ion batteries were in the price range around $1,000/kWh.
Lucky for all of us, 2015 marked a new era as Tesla CEO Elon Musk unveiled the next generation of batteries. both for small consumers and large companies. Prices will start around $350/kWh and will only get cheaper from there.
But solar energy storage only matters if we can produce more electricity than we need so that we can store the excess, so we also need to talk about solar cell efficiency .
The average American household needs about 24 kWh per day (or 1 kWh). However, this figure is unevenly distributed: electricity consumption is relatively constant during the day, increases sharply in the evenings after people return from work, and then practically drops after everyone has gone to sleep. This presents a problem.
In order to have electricity at night, solar energy must be collected and stored during the day, while the sun is still out. But if people use electricity in during the day, the solar cells must capture as much sun as possible: enough to meet the electricity demand during the day and enough to charge the batteries overnight.
Or, to put it another way, if we assume that we get six hours of «good sun» per day — and that’s generous — then the solar capacity should be enough to capture 24 hours of energy during that six-hour period. After all, solar cell ratings are based on ideal conditions: a clear sun at noon at the Earth’s equator.
So let’s talk about efficiency. On average, consumer sized solar panels can generate about 10 Wh/sq. Foot. Therefore, to generate 1 kW / h, you need 100 sq. Feet of solar panels. But that assumes that the sun shines all day every day, and we know it doesn’t.
If we assume six hours of «good sun», then we need four times as many solar panels, giving us up to 400 sq. Feet of solar panels to meet the electricity needs of the average American household. And the sum of all this skin should be estimated at 4 kW.
At an average cost of $5 per watt, a 4kW system would cost about $20,000. Thanks to Tesla, we can now purchase three 10kWh batteries for $3,500 each for a total of $10,500. So for about $30,500 you could have an operating system that satisfies your daily power needs and up to 30 hours of battery life (assuming you have 400 sq ft of land compatible with the panels).
Of course, all this assumes that you have 400 sq. Feet of ground compatible with panels, which is simply not true for most people (especially in urban areas). For this to be a real, practical solution, we would need to greatly increase the efficiency of solar cells, or cover almost all buildings with them, using something like a sprayed solar cell. technology.
Finally, we have big problems with regard to solar energy infrastructure around the world. The crux of the issue boils down to this: think of everything that currently runs on fossil fuels (like cars, power plants, etc.) and then think how much work it would take to convert all this compatible with solar energy.
Many power plants have to be shut down, even demolished, in order to be rebuilt as solar farms. Gas, diesel and hybrid vehicles should move away from all-electric vehicles such as Tesla. And then there are peripheral costs, like converting petrol stations into charging stations.
It’s all very expensive .
But if we look at the future of large-scale solar infrastructure, MIT has just released a study that shows it is possible to achieve terawatt-scale solar power deployment by 2050. That’s enough to supply 41.7 billion households with America’s average electricity consumption.