The advance of technology is making renewable energy economically competitive to fossil fuels. Standard photovoltaic has now an efficiency exceeding 15%, crystalline silicon panels have reached 20% efficiency and in the labs the most advanced solutions have reached 25% (the record has reached in 2016 34.5% efficiency, close to the theoretical limit, for unfocussed light, and 41.1% for focussed light, see chart in the figure).
By 2050 it is a given that technology will have evolved much more making PV better than fossil fuel in terms of cost per KW. How is it that forecasts are not seeing 100% of PV penetration (look at second figure) by 2050 but a good, yet small, 11%?
I am talking about PV because so far, and in perspective, it is the best renewable we can have, since the Sun will be shining for a few billion years more and the amount of energy we receive any day on the Earth surface is way bigger than our needs:
- Sun energy reaching the Earth: 1 billion TWh
- Total use of energy (in 2012) by humans: 0.000149842 billion TWh
- of which electricity (in 2012): 0.000018626 billion TWh
By 2050 we are going to have a mix of renewable sources (as we have today, including wind turbines, geothermal, hydroelectric,...) and they are likely to make a significant portion of the energy sources used:
- Europe in its Energy roadmap to 2050 is pledging to reduce the carbon emission by 80% relative to 1990 (which roughly correspond to a symmetrical use of 80% of renewable energy -not exactly but in that ballpark);
- US expect to satisfy 80% of its electricity need in 2050 through renewable sources;
- 50 Countries most vulnerable by climate change (and by CO2 emission) have pledged to become 100% based on renewable energy by 2050.
Unfortunately, energy usage effectiveness is also dependent on two other factors that do not go hand in hand with renewable: density and continuous availability. I'll deal with this in the next post.