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which PV system?

(36 posts) (11 voices)

Started 2 years ago by greensmonster
Latest reply from Sunshine

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ghostgum
Member

Sunshine, I understand what you are saying, but disagree on the interpretation of how green power / RECs work. You said "RECs has no relevance to the amount of power a wind or solar power system can produce.". The REC rating of a unit is the amount of energy that a wind or solar power system can produce over its life. One REC is one megawatt hour (3600MJ) of renewable energy.

You said "That statement makes no sense, if a person installs wind or solar power system, then the amount of renewable energy produced in the country is increased by the capability of what that system can produce." But I say that your statement is only correct if it is in addition to existing or planned renewable energy generation, rather than used instead of commercial renewable energy generation.

The amount of renewable energy the power company must buy is the greater of either the mandatory renewable energy target (MRET), or the amount of green power that the customers buy. If you install solar PV on your roof and sell the power & RECs, then you contribute towards the MRET (unless this has already been reached). If you don't sell the RECs, then the energy from your panels can not be sold to others as green power, and does not contributed towards the MRET.

The power company buys two things from renewable energy producers: the power generated from the PV solar or wind systems (reducing the power they source from coal), and the RECs that show that the power was from a renewable resource. Unless they buy the RECs, they can't sell it as green power.

Power isn't green - it is made up of electrons, one of the main ingredients of ozone What matters is how much energy from renewable resources is fed into the grid, not where the electrons travel.

It is a chicken and egg problem. Without renewable power sources, they can't sell green power. Without customers wishing to buy green power, there isn't much incentive to install renewable power sources. To kick start the latter, the MRET says they have to buy a certain amount of renewable energy even if no one wants to buy it.

Posted Thursday 29 Oct 2009 @ 3:40:12 am from IP #
rockabye
Member

I have to admit I find this constant debate over which technology is greener than the other, or what should and shouldn't get REC's etc, is very pessimistic approach to what is happening in the real world. To me all of these words and argument over 'paper numbers' is well and truly being overtaken by the actions of many ordinary people.

We should be rejoicing in the fact that the solar, hws, insulation etc rebate scheme(s) in recent years have seen a massive uptake by people who, in many cases, couldn't care less about the environment. But they have voted with their feet and jumped to take advantage of subsidies which ultimately mean less energy is required to be produced with fossil fuels than would otherwise have been required.

Along the way they have launched serious numbers of businesses into 'green job' opportunities. Sure there are the rorters and the dodgy workmanship claims but the vast majority are making a difference. What a change from the previous couple of decades. If someone installs PV or an efficient hws to save money, who cares, the outcome is the same as someone who does it to save the environment. If the REC's are used to created paper wealth or paper mache the solar or heatpump hws is going to need less power than if nothing was done.

So let's celebrate the change that is now occurring at the street level because despite all the political waffle we hear everyday. Look at the massive price drops in PV costs that is occurring, we would have been dancing in the streets years ago if we could have accessed those prices before. I take the optimistic view, and think this is just the beginning.

Posted Thursday 29 Oct 2009 @ 5:41:28 am from IP #
greennovice
Member

Can someone tell me what is maximum size system that can be installed on a single phase meter connection in Perth. Under the old $8000 rebate.

Posted Tuesday 15 Dec 2009 @ 8:40:33 am from IP #
POV
Member

Hi folks, Robyn from Fremantle here for the first time. I fell into this thread while seeking out latest "how to choose PVs for Dummies".

Thank you Rockabye for your 'cup half full' prod. We so need to celebrate in order to ground attention and action for the future. I find the slowness of the bleeding obvious frustrating too. And I wept with joy the first time I saw the Albany wind farm, I felt so relieved and re-activated.

My investigation is to collate options/recommendations for PVs for Pinakarri Community in Hamilton Hill near Freo. Pinakarri is a cooperatively managed, sustainability driven, urban intentional community, which combines CH rental with privately owned houses designed using cohousing design and intention. Scope is for rental coop houses and common house: 6 large, unemcumbered north-facing roofs (2 story), 6 lower, smaller rooftops. Pinakarri provides, facilitates or supports education for sustainability with tours, workshops, presentations, community dinners and celebrations.

Did anyone collate or conclude anything from the earlier conversation? Any good learning to share? I'm in the communication side of sustainability and my technical comprehension is modest. I did find a 'Dummies' intro free to view at Choice which could be useful for other newbies:

SOLAR PANELS BUYING GUIDE
http://www.choice.com.au/Reviews-and-Tests/Household/Energy-and-water/Solar/Solar-panels-counting-the-cost/Page/Installing%20solar%20panels.aspx

Thanks for your time, may meet some of you at an ATA meeting in 2010.

cheers
Robyn Williams
POV

Posted Thursday 31 Dec 2009 @ 3:05:25 am from IP #
Anonymous
Unregistered

"Can someone tell me what is maximum size system that can be installed on a single phase meter connection in Perth. Under the old $8000 rebate.
Posted 3 weeks ago #"....

Hello greennovice!

I have been asking a similar question here in Vic. All the retailers just say you can install whatever size you like (most likely because not many people would consider spending the $ to get anything HUGE).

I too have qualified for the $8,000 rebate and have been shocked to discover -in calling around for quotes to increase the size of the system to be installed- that it appears to have a value of $1,500 with solar retailers.

For eg. State Solar offer a 1.5kw system for $3,999, which reduces to $2,500 with the $8,000 rebate. Maybe my calculator is broken? There seem to be something I am missing. Can anyone help? I am in Dromana, Vic.

I am signed up for a free 1kw system at present. I was wondering if anyone out there has tried to upgrade their inverter with the initial installation, with the idea of adding a panel a year to their system (as dollar savings allow)?

Posted Wednesday 6 Jan 2010 @ 9:31:56 pm from IP #
Sunshine
Member

simple.life,

You need to work out what size inverter you want need (for future expansions in mind), and try to match the appropriate panels (whilst keeping voltage ranges compatible with the inverter).
You have to be aware the voltage of the panels varies alot during the year, due to temperature, panel tilt angle, direction in relation to north, season,solar insolation etc.
The voltage output of the panels has to be in the range that the inverter can handle, otherwise the inverter will shut down if the voltage drops too low (like on a hot day), and can fry the inverter if it goes too high (on a cold day).
I have a calculator for measuring compatible panel strings for Sunnyboy SMA inverters. It's amazingly complex how the different variables affect the voltage output range of the panels.
The calculator works out the panel voltage output for temperatures in the range of -15 to 70 degrees celcius.

Posted Thursday 7 Jan 2010 @ 12:01:49 am from IP #

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