How Much Solar Energy Capacity Can We Get from the Sun Each Year?
And What About Other Renewables and Fossil Fuels?
Solar energy capacity is exploding in the U.S., Europe, China, and in other parts of the world. Many projects are small in scale, such as using solar to power water pumps in remote farm locations. But others are huge, saving dozens of MegaWatts from the power grid at single locations.
Many projects are small in scale, such as using solar to power water pumps in remote farm locations. But others are huge, saving dozens of MegaWatts from the power grid at single locations.
All this adds up to a worldwide acceleration in solar energy production. In 2015, solar power surpassed a milestone, now accounting for more than 1% of global energy usage. Solar energy capacity grew 418% from 2010 to 2014, says Clean Technica.
And according to this article at Clean Technica, the world produced 178 GW in solar energy as of 2015, which is the equivalent of 33 coal power plants.
But how much is still possible? The diagram shows the remaining capacity for how much energy we can get from the sun, compared to all other sources. For resources like coal, the diagram shows the energy available from all remaining known reserves. For renewables, it gives the yearly capacity.
The diagram is a little hard to read though, so here’s the data in chart form below. Note: All values are in TeraWatt-years.
What’s a TeraWatt? It’s 1 million MegaWatts, or 1 billion KiloWatts. A typical house uses around 15000 kWh per year. Notice the orange ball on the left side of the diagram. The entire world uses 16 TW-years per year. So that puts things in perspective.
Global Energy Capacity and Reserves, from Renewables and Non-Renewables
| Energy Source | Capacity (TW-yrs) |
| Solar | 23,000 |
| Tides | 0.3 |
| Geothermal | 0.3-2 |
| Hydropower (dams) | 3-4 |
| Biomass | 2-6 |
| OTEC (oceans) | 3-11 |
| Wind | 25-70 |
| Waves | 0.2-2 |
| Coal | 900 |
| Uranium (nuclear) | 90-300 |
| Petroleum (oil) | 240 |
| Natural gas | 215 |
Why do some of them have ranges? In some cases, the weather variations from year to year will have an effect on the energy that can be collected from these sources. Also, as technology improves, the efficiency of extracting usable energy from many of these sources will extend these numbers. And finally, not all reserves are necessarily known or easily accessible.
For example, in the 80s we were told oil would run out by the 2020s. Since then technology has improved and more reserves have been found. So projections in terms of energy are not iron-clad.
Solar Energy: The Most Untapped Source of Energy, By Far
But just look at the scale of the numbers. Even if super-extreme inaccuracies were found in these numbers, or huge new discoveries were made, or we expanded to other planets and found huge loads of fossil fuels (unlikely) or uranium, just play some hypothetical games and solar still dominates.
For example, what if we doubled the amount of known coal reserves? DOUBLED. That’s a lot of coal we somehow don’t know about. But if this doubled, the total reserves now stand at 1800 TW-yrs. This is still almost 13 times less than the existing energy potential of solar.
What to Tell Your Friends about Solar Energy Potential
The takeaway is pretty simple. Solar energy has the potential to supply thousands of times more of our energy needs than we’re now using.
The only things holding us back are available surface area, initial costs (which are coming down fast and can be slashed by 30-50% more using various solar power tax incentives, and the uncertainties of people like us.
What’s at stake here is the future of energy use. The world’s population is growing. And modern technology is spreading. That means we will need way more energy than we do now if we want to sustain growth and spread it to nations that still haven’t received the benefits.
And remember – something as simple as a water pump is all it takes to realize the benefits of clean and nearly unlimited solar energy.
Considering Solar?
If you’re just starting out with solar, there is also a learning curve. You can’t just go out and buy solar panels next week. Here are a few resources to get started.
Learn how solar works – the basic science behind the panels
On-grid vs Off-grid – 6 questions to ask to help make your decision
The top 11 benefits of solar power
How much does solar power cost?