Urban oil men

In the US alone, 150 million gallons of diesel are burned every day, resulting in tonnes of carbon dioxide and black carbon being emitted into the atmosphere. And while there has been a surge in cleaner biofuels, they have been criticised for driving deforestation and competing with food crops for land and water.

But in New Jersey, US, entrepreneurs are combining American’s love of fast food with its need for fuel by collecting and filtering used cooking oil so it can be turned into biodiesel.

Russell Beard hits the streets of New York with workers from Grease Lightning, one of a number of companies now collecting used cooking oil from thousands of restaurants. He finds out how grease once illegally dumped and left to clog drains is now so sought after that even criminals are after it.

Sugar plastic 

Every year hundreds of millions of tonnes of plastic are produced to meet our growing appetite for the material. Plastic is everywhere - and it is choking not just the land but our marine life too.

So a natural alternative made from sugar beet waste may just be the answer to our destructive love affair with plastic.

A company in Italy called Bio-on has found that bacteria that feed off sugar beet waste can be manipulated to create a biodegradable alternative to plastic.

Giorgia Scaturro is in Bologna, Italy, to see whether this bioplastic could offer a solution to a growing environmental problem.

Round the clock renewables 

One of the biggest challenges facing the renewable energy industry is the inconsistency of the power that renewables supply.

If conditions are good, wind, sun and sea may generate more electricity than the grid can take, but at other times they may not produce enough.

One solution to this problem is to store up surplus renewable power, so it can be released when it is needed. And British company Highview Power Storage have come up with a new way of doing this, using a resource that is all around us - air.

Using off peak electricity - which could come from a wind or solar farm - Highview’s pilot plant cools and compresses air to -196°C, the temperature at which air’s main component, nitrogen, becomes liquid. This liquid is then stored in tanks, and when electricity is needed again the liquid air is warmed up, causing it to expand and drive a turbine.

The plant effectively operates as a battery, and at a commercial scale could be used to make renewable power sources more reliable, and more competitive with fossil fuels.

Unlike other energy storage devices, liquid air plants could be located anywhere, and they use existing, affordable technology.

Smitha Mundasad is in Slough, UK, to see how liquid air storage technology could help make the most of renewable energy.

Source: Al Jazeera