The speech that Scott Morrison could give in Glasgow, holding a lump of coal in one hand, and a lump of silicon in the other.
— Read on reneweconomy.com.au/coal-and-silicon-the-speech-that-morrison-can-use-to-wow-his-glasgow-audience/

And still more: we are working to make cells that will last up to fifty years. Do the calcs and you will find you will get 350,000 kWh from your piece of silicon, or 140,000 times more than from your piece of coal.