"There's some preparation for the market done at home, but nothing that requires electricity."

These plants use the activated sludge technology which requires electricity.

This filtration system did not require electricity and could potentially help large groups of people have access to clean water.

'It's clear you no longer require electricity to power on,' he said.

Slow sand filters do not require chemicals or electricity to operate.

"It requires electricity so it's difficult to take with you for warming up prior to an event," he said.

The system is easy to operate, and does not require electricity, making it ideal for rural settings.

But to activate it would require electricity of some sort.

However, most heating systems require electricity for their operation.

This requires electricity to be transmitted north through a power grid which is reaching its capacity more often.