If lily pads on a pond double the area they cover every day, and it takes 48 days to cover the pond, how long does it take them to cover 50% of the pond? (Answer at the bottom.)
The world is still looking for cost-effective substitutes for fossil fuels. Popular opinion still is heavily against nuclear, and environmental advocates still lobby against hydroelectric installations–at least in the developed world. (They don’t like it in emerging countries either, but they don’t get listened to quite as much down south.)
What’s available is wind, biofuels and solar. Wind and biofuels are stuck in controversy, so what is acceptable is solar.
Solar is hampered by its intermittent nature, unable to dispatch energy 24/7.
However, despite its cost and intermittency, solar power continues to grow. This actually seems to frustrate those who rely on free market economic theory, as they don’t understand why people buy solar installations for their rooftop when it is more expensive than other sources of energy. They don’t seem to understand that there are more signals in a free market than price. Solar can be a vanity purchase, a hedge, a political signal a Veblen good–all of these can explain many of the purchases of solar power.
In 2014 global solar installations grew by 20%, to 42 GW, certainly not solar’s best year. Those installations, when added to those of previous years, mean that solar power is making a contribution to global totals. However, despite impressive growth, it is still an asterisk in world energy consumption.
Solar can show impressive curves when measured by itself. But when you look at global totals it is not so impressive.
Solar power continues to get cheaper. Five years ago the average household income of a household buying solar was $150,000. Now households earning half that can think about solar if they choose.
Solar is still more expensive than the alternatives, however, when you look at the Levelized Cost Of Energy.
So, assuming that solar power grows at 20% a year, driven by falling prices, environmental concerns and rising utility costs (which seem to pay no attention at all to the cost of fuel), what will solar look like in the near term future?
Solar power provided about 2% of all renewable energy in 2013, or about 1.12 quads. If it continues to grow at 20% a year (which is slower than the rate at which it grew in the past two decades) its delivered energy will amount to:
2020: 4 quads
2025: 10 quads
2030: 25 quads
2035: 61 quads
2040: 153 quads
2050: 952 quads
Sure hope it works out that way.
Answer: 47 days