July 9, 2014

There were 2 posts published on July 9, 2014 (this is page 1 of 1).

Solar has won. Even if coal were free to burn, power stations couldn’t compete | Giles Parkinson | Comment is free | theguardian.com

Astonishing.

Last week, for the first time in memory, the wholesale price of electricity in Queensland fell into negative territory – in the middle of the day.For several days the price, normally around $40-$50 a megawatt hour, hovered in and around zero. Prices were deflated throughout the week, largely because of the influence of one of the newest, biggest power stations in the state – rooftop solar.

“Negative pricing” moves, as they are known, are not uncommon. But they are only supposed to happen at night, when most of the population is mostly asleep, demand is down, and operators of coal fired generators are reluctant to switch off. So they pay others to pick up their output.

That’s not supposed to happen at lunchtime. Daytime prices are supposed to reflect higher demand, when people are awake, office building are in use, factories are in production. That’s when fossil fuel generators would normally be making most of their money.

via Solar has won. Even if coal were free to burn, power stations couldn't compete | Giles Parkinson | Comment is free | theguardian.com.

Segway Inventor Dean Kamen Thinks His New Stirling Engine Will Get You Off The Grid For Under $10K

For the new issue of Forbes Magazine I wrote an article about David Crane, the visionary CEO of NRG Energy. When I met Crane for lunch a couple weeks ago, no sooner had we sat down than he began singing the praises of this new contraption he had in his basement. The machine — which can generate 10 kilowatts of continuous power, fed by Crane’s natural gas line — is a new iteration of an old creation, the Stirling engine. This version, called the Beacon 10, was created after a decade of engineering by famed inventor Dean Kamen.

With the Beacon 10, says Kamen, “you don’t have to feel guilty heating up the pool.” That’s because of the highly efficient nature of the Stirling engine. First conceived in 1816 by Scottish minister Robert Stirling, the device in its simplest form consists of applying an external heat source to a closed cylinder where the cyclical expansion and compression of air inside the cylinder drives the pistons up and down. Unlike your car, where fuel is combusted inside the engine, the Stirling is an external combustion engine; it can work with any external heat source.

via Segway Inventor Dean Kamen Thinks His New Stirling Engine Will Get You Off The Grid For Under $10K.