I think what needs to be considered here is what we consider a waste of electricity. Efficiency calculations are dependent on waste, So I personally think electric cars are a waste of resources, they consume electricity to run and consume non renewable resources to produce just to move a maximum of 1-5* people per journey. Whereas an electric which still uses this resources can move over 10x that amount per journey, and trains over 30x that amount per journey.
So to me that's energy inefficiency at the consumer point.
Now let's look at energy generation and transfer. At the moment, alot of energy production is a for profit business, Company A builds a solar farm, Company B builds a Coal power plant and Company C (This would be overseen by the government, not a private company) builds a nuclear reactor. All 3 of these companies produce various amounts of electricity with different efficiencies, but all must be sold at the same price. It might only cost £0.01/KwH on the solar farm to produce, but must be sold for £0.33/KwH, the coal would be £0.27/KwH and nuclear would be £0.45/KwH.
You have 3 generation methods, each with strengths and weaknesses all being forced to sell for the same price. Normally in a capitalist system you see "Competition" (not really) on the market. Company A would say "We're cheap, but can only guarantee 97% uptime due XYZ issues", most homes would be fine with me this. Company B + C "We're not as cheap but we can offer 99.9% uptime" This looks great for companies needing that security in uptime.
I've gone on a tangent and can't be bothered finishing this post maybe someone else will.