The following question was recently posted on Quora:
“What are the countries with the highest renewable energy generation (by percent of energy use)? What factors lead to being able to rely so much on renewables?”
Compare the following responses from three energy experts:
Alex Lightman, Chairman of 3 Tech Companies:
There are 45 nations that get 90% or more of their electricity from renewable sources.
There is no other nation even remotely oar to Paraguay, which gets 1,000% of its electricity from hydropower dams (that it shares with Brazil). That is, Paraguay gets 100% of its electricity from hydropower and exports 9-10x this amount.
Iceland also gets 100% of its electricity from renewables, 76% from hydro and 24% from geothermal, and heats with geothermal energy as well, but it doesn’t export energy like Paraguay.
\What factors lead to the being able to rely so much on renewables\
Main factor is hydro. Hydro is relatively cheap. Hydro can become baseload, load following or energy storage.
Since hydro is cheap, renewable and it can become baseload, load following or energy storage, then you can build nothing but hydro and have a 100% renewable grid with no blackouts and with relatively low electricity costs.
For europe, it has hydro relatively nearby. With lots of hydro in the european mountains and of course in the big producers, the scandanavian countries. Since its nearby but not in all countries, Europe has constructed electricity cables to transfer and share electricity among the various coutnries.
Without this connection to the big hydro producers, its doubtful that Europe could continue building solar and wind beyond a certain percentage. This is because wind and solar are intermittent and hydro can become energy storage or load following . Without batteries or some sort of backup (like fossil fuel plants that are paid to be idle only to spring into action when needed) a future europe with minimal amounts of fossil fuel or nuclear electricity generation would need to import a large amount of power from the scandanavian hydro plants if its a non windy night. Its is because of the large amounts of scandanavian hydro available that the prospect of Europe powered with large amounts of solar and wind is borderline plausible. It also doesnt hurt that europe is rich and doesnt have a steep electricity demand growth curve.
Since europe shares electricity, its not fair to single out any one country or any one region and say this one has X percent of all power produced by Y energy source. You have to look at europe asa whole. Analogous to an island with one interconnected electricity grid but the west side has only fossil fuel plants while the east side has nothing but wind and solar. It would of course be dishonest to cherry pick just the east side of the island and say its 100% powered by renewables since the east side imports a lot of electricity from the west when its a non inwdy night.
A lot of areas dont have large amounts of in country or nearby hydro resources. Without such cheap energy storage options available, this would put a limit on the percentage of wind and solar that can be integrated into their grid.
Ashish Verma, solar photovoltaic technology, project planning, energy policy expert:
The leading countries in terms of renewable energy penetration in overall energy consumption are,
1. Germany- country where wind and solar both contribute 60% in energy consultation during peak season. Rest of the time both contribute around 20% of their energy consumption. that is goodbye sign
2. USA- overall contribution of renewable energy in terms of end energy consumption is around 5-10% but state like california has shares of 40% in overall power consumption during peak summer season.
Obviously Denmark, Spain are also having share of approximately 10-15% in overall consumption.