Wind, solar sustainable if excess power is stored

I refer to the commentary “Why wind and solar power are not solutions to climate change” (Nov 10).

The writer suggested that wind and solar power are not cost-efficient because they account for a small percentage of total energy used and their low market share means they must compete below market price with conventional energy.

And as those two energy sources are not always available, fossil fuel plants must be subsidised to provide backup power, and the plants will not cover the construction costs and other fixed expenses if they are used less often.

However, those plants can be run 57 per cent of the time to avoid losses, as the writer mentioned, while wind and solar power can be used for the remaining period; the excess power generated can be stored as backup.

With this arrangement, governments do not have to subsidise the building of fossil fuel plants. Also, as wind and solar energy are allocated a market share, they will able to command prices near the market value.

This will require coordination between government agencies and the various energy providers, so that an economically sustainable energy-grid system can be developed. Leaving this to free market forces would result in an unsustainable system.