Hybrid solar: How to kiss the grid goodbye (Australia)

[kristopher]

Hybrid solar: How to kiss the grid goodbye
By Jeff Bye on 30 March 2012

If ever there were a need to develop off-grid power systems it would have to be now, when transmission costs are now up to around 60 per cent of non-solar power bills.

Solar systems have historically been classified into two broad camps – “grid connected” or “off-grid” systems. This distinction has arisen due to historical segments of the market that needed solar to do different things. The vast majority of systems we see around Australia’s towns and cities are grid connected and have been driven by feed-in-tariffs and consumer desires to cut electricity costs and do something positive for the environment.

Off-grid systems have historically been the preserve of regional customers seeking to avoid expensive network augmentation costs to provide power to their remote locations. Off-grid systems are usually a lot more expensive as they require battery storage, more complicated control technology and often diesel backup generators to ensure the lights will always shine. Battery technology has also been a culprit as the memory effect of old-style lead-acid batteries has meant that battery arrays are oversized to ensure the depth of discharge is not high and hence battery life is extended.

An emerging trend though is for so-called hybrid systems which take a little from column A, and a little from column B. Such systems could either be described as an off-grid system which uses the grid as the standby generator or a grid-connected system with some added battery storage. Either way, these systems don’t require expensive diesel generators since the grid provides that service, and the size of the battery arrays can be downgraded as the cost of back-up power using off-peak grid electricity is much lower than that provided by diesel generators.

The technology that is making this possible is a new generation of products capable of directing energy flows as the consumer best desires...

http://reneweconomy.com.au/2012/hybrid-solar-how-to-kiss-the-grid-goodbye-59957

[intaglio]

1. Will someone please come up with a cheap, feel-safe battery

I've seen the TED talk with the molten salt battery - but marketing a home version would be very difficult (molten salt? molten metal??!!) and I have met someone who buys used lead acid batteries from scrapyards (vehicle dismantlers) but an off the shelf solution is urgently needed.

[Fumesucker]

5. Hybrid vehicle batteries from wrecked cars would be one option for a homebrew unit..

They last so long that the price is not that bad on the junkyard market..

http://www.hybridcars.com/fleets/taxis-show-hybrid-battery-durability-25167.html

“Only two of our 182 hybrid battery packs have had to be replaced during the years hybrids have been a part of the city’s taxi fleets,” Gillespie said. “One was replaced under warranty and the other was driver error.” The taxis in the city average 90,000 miles a year.

Years of Service and Savings for Hybrid Taxis

San Francisco's first hybrid taxi was a Toyota Prius that went into operation in 2003. The first fleet of hybrid taxis anywhere in America hit the streets of San Francisco in November 2004, with fifteen Ford Escape hybrids operated by Yellow and Luxor cabs. The city also has Camry hybrids in its hybrid fleets. In Vancouver, British Columbia, a city teeming with Prius taxis, Andrew Grant started using a Prius as a taxi in 2001—and rolled up more than 300,000 miles without battery problems.

Gillespie said hybrids are popular with drivers due to the “tremendous savings” in fuel costs, which the city estimates at $9,000 a year compared to a gasoline Ford Crown Vic, the traditional vehicle used in cabs. In addition to fuel savings, the city also has a subsidy that is only available to hybrid cabs. Gillespie added that cab company managers, for the most part, have been open minded, waiting to see how the vehicles hold up to the grueling conditions of a San Francisco taxi.

With more than three years of operation under their belt, hybrids are now considered a proven alternative for cab companies. Their experience in San Francisco also points out that ordinary consumers should not have to replace their hybrid battery during the life of the vehicle.

[DCKit]

2. Only works where you have reliable grid service.

Where I'm headed, power is lost often, and they have constant fluctuations. One friend, with a house full of electronics, is often raging on the subject.

Ice storm are a high probability, and the last big one (a long time back, to be honest) left most of two counties without power for two weeks.

In the meantime, our house is off-grid and we just have to suck up the cost of batteries... which, over the past twelve years, is still less than we would have been charged for running power lines for the privilege of paying a monthly electric bill. The system we've got (totally adequate), would cost less then half what it did, now.

[kristopher]

3. Well, from the authors perspective poor grid reliability is a reason for investing in this set-up

My grid keeps dropping out! Many solar consumers ask the question about what happens when the grid goes down? Unfortunately the answer they get is “so does your solar system in order to prevent injury to electrical line workers”. Having a hybrid model appeals to consumers who are looking for higher levels of reliability than their existing supply. A hybrid model would allow the home to effortlessly switch from solar to grid to battery as the need arises on a least-cost basis.

This is predicated on products and services available in Australia that may not be on the market everywhere.

The technology that is making this possible is a new generation of products capable of directing energy flows as the consumer best desires. One such product is the PowerRouter which enables the home owner to optimise, control and manage any self-generated electricity. A homeowner in NSW appalled by their retailer’s offer for solar buyback, for instance, could arrange for excess solar yield to be diverted to their batteries for use at another time when electricity prices are higher. The batteries could also be re-charged on off-peak tariffs and re-used during peak periods as a straight arbitrage opportunity.

I think we will see some major regulatory streamlining as EVs with V2G become a common item, but until then wading through the morass of regulatory fiefdoms is a major undertaking for anyone interested in taking more control over their energy.

[DCKit]

4. Add to that, I've been thinking much about adding an LP generator for co-generation.

May as well heat the house and hot water while producing electricity. It gets cold where I want to live. Even in a worst-case scenario, I'd be covered.

Using the wast heat from the engine for heat and hot water doesn't raise the efficiency to 100%, but it's better than just burning it once.