Last month, Tesla announced all the information people need to order the company’s solar rooftiles. One particular piece of information has been more anticipated than the others – the price.

Elon Musk hinted last year that the solar roofs would cost less than regular roofs after energy savings were taken into account, but now it seems that they’ll be cheaper even before they start generating power.

According to Tesla, the average homeowner will pay $US21.85 per square foot of solar roofing.

However, one thing people need to understand is that not all of the tiles will generate electricity. Some tiles will be in areas that are overshadowed – by trees, or overhanging structures, for example, so there’s no point in them being solar. The $US21.85 price is for a roof on which 35% of the tiles are solar. Other people will be able to have up to 70% solar tiles, but the solar tiles cost $US42.00 per square foot.

The roof will more than pay for itself

The Tesla website offers two example of a house in Maryland with either 70% solar or 40% solar tiles. The 70% option earned $US67,300 in energy over 30 years. This, combined with a $US19,600 tax credit, minus the $US64,800 cost of the roof and the $US7,000 spent on a Powerwall 2.0, means net earnings of $US15,100 over 30 years.

The solar roof tiles are made from tempered glass and have an infinite warranty; Tesla expects them to generate electricity for at least 30 years. These tiles are also three times as tough and durable as either terracotta or slate tiles and it’s this durability that makes solar roofs such a great investment.

It’s expected that the installation of a solar roof should take between five and seven days, including the removal of the original roof. The Tesla roof is perfect for anyone who wants to go solar and needs a new roof in the near future.

Installations outside the US expected to start in 2018.