What costs between €400 and €500 (£290 and £360) to set up, requires a fibre-optic connection, is sold by a company that has the uncoolest name ever, and provides 1000 watts of free heating forever? The Nerdalize eRadiator, which is now being rolled out to households in the Netherlands.

Back in 2011, Microsoft Research published a research paper on the topic of data furnaces. The concept was simple. Microsoft has a lot of servers, mostly sitting in large data centres, producing huge amounts of heat—heat that is a massive nuisance to deal with. Instead of venting that heat into the environment (and spending a fortune in the process), why not do something useful with it?

Finding ways of dealing with waste heat from data centres and supercomputers has been a hot topic over the past few years, primarily due to the huge costs involved. Cooling a large installation of computers can account for a large percentage (upwards of 30 percent) of day-to-day operating costs.

Way back in 2008, IBM installed a data centre in Zurich that uses waste heat to warm a nearby town's swimming pool. In 2011, Google built a data centre in Finland that uses cold sea water for cooling. Facebook has a facility in Lulea, Sweden, on the edge of the Arctic Circle, that is powered entirely by hydroelectricity—and the reliably cold outside air reduces cooling costs considerably, too. Most of the Web's larger service providers, which stand to gain the most from such solutions, are in the process of setting up these "green" (i.e. more energy efficient) data centres.

Microsoft's data furnace idea was a little more... decentralised. Instead of finding a novel way of transferring waste heat away from the data centre, the research paper proposed that the servers themselves should be placed in homes and offices, where the waste heat could be used directly. It was a very clever idea with a lot of potential benefits, but it had a couple of big problems as well: namely, data security and connectivity.

Nerdalize is a small Dutch company that is trying to commercialise Microsoft's data furnace idea. The first product is the eRadiator, which, given its size, probably contains two or three servers that pump out around 1000W of heat—probably just enough to heat a small room in winter. In an interview with the BBC, one of the first users of the eRadiator says it takes "about an hour" to heat up.

To be eligible for the eRadiator, your home has to have a "fibre-optic connection" and "an external wall." The fibre link is necessary to connect the eRadiator to Nerdalize's core network, and the external wall is needed for venting (if you "turn off" the eRadiator, the servers don't actually turn off; the heat is just pushed outside).

In exchange for free heating (after the €400-500 setup cost), Nerdalize uses the network of eRadiators to provide a cloud computing service. Because the company doesn't run a centralised data centre, operating costs are much lower, which means the "cost-per-job [to the customer] is up to 55% lower." The quality-of-service will be be lower than centralised cloud compute, too—Nerdalize won't have any control over the access network (what if the home owner decides to do some torrenting?)—but there are plenty of use cases where cost is more important than latency.

Nerdalize's radiators are in a tamper-proof case, and the servers use encrypted file systems, but data security is still very much an issue; there will be a lot of customers who simply won't use Nerdalize because they don't want their data to be stored in an insecure location. On the flip side, there is some argument to be made that the decentralised nature of the eRadiators makes the data more secure: "It becomes nearly impossible to know what data is where, when it is there and how to get to it," Nerdalize's Florian Schneider told the BBC.

Perhaps the biggest problem with Nerdalize's approach, however, is maintenance and reliability. What happens when a server breaks down? The Nerdalize FAQ says that "service calls will be necessary" for more severe problems. What if the customer forgets to pay the bill for the Internet? Or a fuse blows?

Still, when a data furnace company eventually opens up in the UK, I'll be keen to get some eRadiators installed at home.