How Home solar panels can help stabilize the grid, part 2 of 2?

Editor's Note: Scientific American George Musser will be on their experiences in the installation of solar panels in the solar home (formerly 60-second solar). Read his introduction here and see all the posts here .

The first installment of this post, Arnold McKinley Xslent energy technology describes how "reactive power" - i.e., stored temporarily by electrical appliances and then released power - destabilizes the network eléctrica.Aquí explains how home can help solar panels.

Traditionally distributed electricity using a grid of wheel and speaks: power travels from a large generator plant loads distributed around. In some cases, energy travels very long distance perhaps of 500 to 1,000 miles, before being used. This model is changing.From solar and wind energy at numerous points of local injection, the grid is coming to look more like a network of as a wheel - making it even more difficult than it already is keep power flowing without problemas.Dos recent developments promise to help to. The first is a new generation of microinverters and the second is the growth of the intelligent grid interconnected.

A solar panel generates power DC, converted to alternating current by a device known as an investor. Most investors require a certain minimum threshold voltage to work. Therefore, panels should be wired together electric series to raise sufficiently high tension. Experience has shown this configuration is less efficient, optimally as a previous solar home post has spoken. A cloud shadowing of one panel reduces the efficiency of the entire string.Furthermore, each panel has slightly different electrical, creating a mismatch that reduces the energy generated characteristics.Finally, if the chain tension is too low, the investor never turns; therefore in the days of rain or fog, system neutral no power absoluto.La solution to all problems of three is to adjust to each panel with your own investor low voltage or microinverter. Lit as soon as light falls on the panel and automatically compensates for electrical panels differences.

But if microinverters were also capable of producing reactive energy, could send excess consumption of local loading in the grid, which vigorously active now, and help utilities.

The figure on the left provides an example of a basic configuration in household appliances draw 1000 Watt active and reactive power 600 voltios-amplificadores. If a solar array generate 1200 W power, then, is capable of producing 1200 W AC power active and 1200 VA reagent AC power. This is not only enough to power the House, but also to feed some power active and reactive in the grid. All you require is the microinverter right.

When ordinary investors and microinverters developed firstly, designers do not pay any attention to the generation of reactive power. Since consumers are paying only for active power, the goal was to produce both of you as possible. Today it is clear that reactive solar producers can help stabilize the grid, and microinverters are being designed to produce both. In fact, physics is helping us here.Since no energy is required to produce the reactive power, an investor can produce without sacrificing the active power or requiring more solar panels.

When he first learned that reactive power can occur without affecting the active component, I was surprised.To see that this is reality and not fantasy, the figure on the right shows two days of energy production in a typical installation of first solar.El day, the microinverter was created for active energy (green line) and reactive power (red line);the second was created to produce only active energy.Switch did not affect the production of active energy at all.My company website has more details on this issue.

In the past, the big problem that prevents the production of reactive power of microinverters was heavy capacitors need store energy form temporal.Pero new designs serve the trick simply by changing the way AC.Esto wave significantly reduces the cost and size of the devices.

Thing that Moreover, microinverters are also evolving to communicate with other network devices, both are already doing smart meters .Microinverters network can report data for display in Web browsers, but some also have two-way communication, which allows operators to control their mix of generation of active power and reactiva.Finalmente, onboard intelligence adjust the mix on the fly, offer the best economic benefit consumers that based on their rate (which will eventually include the pricing of reactive power) structures .Esa intelligence will enable these distributed networks to separate from the main grid of continental and is localized microgrids that generates electricity we need when we need it.

Photo and diagram courtesy of Arnold McKinley