Wednesday, July 29, 2009

Solar AC Output

I actually do not buy this effort at all. The power densities are way too mismatched to plausibly be put together this way with any economic convenience. Of course I am willing to be surprised again.

The more interesting point is that it is plausible to convert buildings to DC power systems, if it can be done safely at all. So much equipment is DC it seems obvious, yet our power consumption is from the fridge and the stove and other associated power pigs. DC becomes tricky here.

Super storage and associated direct current avoids a lot of loss, so we may yet be going there. Dribbling energy into an application super capacitor all day avoids the heat risk by having it reside close to the application.

Certainly, we are well into the needed tech to create a whole new home energy system and initially it still needs to have access to both types of supply somehow. Quite clearly this is a problem that calls for a top down mandated clever engineering solution that is also easily retrofitted.

The key is to start thinking about all this and to try out various options. Direct current straight of the roof is a resource. Pushing that resource into a super capacitor seems to be an obvious first step, if only because all applications are typically intermittent. And that is the real answer. All these problems are because of our difficulties with storage technology and that problem appears to be realistically on the verge of resolution.

The moment that I can collect solar all day and store it with a minimal loss in a super capacitor battery to be then drained in the morning into my vehicle for transportation with also a minimal loss, is the moment that all these problems and options become easy and directly resolved. In short, hang on a little and we may well have it all licked.


New Solar Panel Goes Straight To AC

Written by Yoni Levinson on 22/07/09

The electricity that comes out of a photovoltaic panel is always DC. Since our buildings tend to use AC electricity, that means that a standard part of every PV solar installation is installing a big inverter to take the DC input from the panels and produce an AC output which is identical to what’s coming from the local power line.It’s possible, though, to build small inverters (aptly named microinverters) directly into each solar cell or module; instead of feeding all the electricity through a single, large inverter, you feed small streams of electricity through many small inverters. Startup
GreenRay Solar is getting funding to develop this kind of technology, so that one day a homeowner can buy a solar panel and pretty much install it him/herself. Right now, you usually have to be a licensed electrician to do the electrical work needed to install conventional panels. But GreenRay’s panels would be a lot simpler, because they bypass the inverter step. It still might not be as easy as plugging in an appliance, but it would bring PV installation down a couple notches, within the reach of aspiring DIY-ers.To answer the unasked question – yes, these solar panels will cost more money. But, as GreenRay will tell you, microinverters offer additional benefits. For example, if part of the panel is blocked, it will not affect the other parts. And, if you are the kind of person who wants to carefully monitor your system’s performance, the microinverter panels will give you more precise and detailed information. However, as more and more electric devices require that electricity converted back to DC, and as PV electricity becomes more prevalent, one might wonder why we don’t begin to design DC houses from the start.

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