Calstar Products' bricks use up to 90% less energy to make and generate 85% less carbon dioxide

A Silicon Valley firm has unveiled a low-energy brick that it hopes will revolutionise the market in America.

Bricks made by Calstar Products, require 80-90% less energy to make and the process generats 85% less carbon dioxide than normal bricks in the process, according to the firm.

While ordinary bricks are fired for 24 hours at 1,093 degrees centigrade and can take a week to make, the San Francisco firm has discovered a way to fabricate them at below 100 degrees centigrade. The process takes 10 hours from start to finish.

Bricks have been made in about the same fashion for the past 3,000 years, but Calstar’s product uses a lot of fly ash – a byproduct of coal plants – that helps the chemical make up.

At first, the firm is only planning on making facing bricks but, intends to break out into paving stones, roofing tiles and other brick markets.

The startup is backed by $15m (£9.4m) of VC cash led by Foundation Capital and EnerTech Capital. It hopes to sell 12m or more bricks in the first year and make 100m available for sale throughout the Midwest and South of America.

Paul Holland, a partner at Foundation, said: “We think it is time for a second industrial revolution.”