Thread: Just getting started on Solar HWS/Power investigations

Originally Posted by Slunnie

Im currently building and have just decided to not fit solar, but instead a heat pump tank. Admittedly I live in a cold climate so I probably would have gained limited amounts from a solar setup, but the complexity, risk of break down with the additional systems and cost of a better system has driven me back to a heat pump setup for something that is still cheaper to run, simple and reliable.

I fitted a solar HW to a house about 10 years ago that was in a frost area. The panels faced north so had full sun (no shade). We only needed to use the electric boost 3 or 4 days a year at most. The panels have become more efficient since then and more frost resistant. Solar HW with a gravity fed roof tank is pretty simple as has no electric motor. Heat pumps are a huge improvement over electric and probably $1000 less initial outlay than solar HW. However, you should consider maintenance and depreciation (expected life of system). Most units have sacrifical annodes that are recommended be replaced every 3 to 5 years or somethin (unless you get one that has a stainless tank).

in regards to Solar Power, a standard 1 - 2Kw system ($4-10K) I have often seen customers go from $200 a qtr bills to going in credit.

Getting solar is the first step, but learning to be wise with power can see you actually turn your bills into cheques.


A few things to consider.

you only sell the power you generate but don't use... if your house is pulling 3 kilowatts and your solar is generating 1, then you using it and buying 2 from the grid. So... you don't use power thirsty appliances when you generate.. i.e. during the daylight... you run things like washing machine, dryer, dishwasher etc at night.

if i owned a home, i would most definately get a solar power setup... if you use them wisely you can do well.. my numbers say payback on investment is about 4 years.. which is pretty damn good. And I work in the Electricity industry and see customers Solar bills daily.

Steve

Okay - first up the disclaimer - I am a BCSE accredited grid connected photovoltaic designer / installer (solar electricity) in NSW so I am unashamedly in the FOR camp.

Now, onto the reasoning, realistically the most effective ways to reduce your home energy usage are, more or less in order of energy effectiveness:

1) Replace / reduce use of energy intensive appliances - e.g. low voltage halogen lights, unplug appliances when not in use etc. Believe it or not the average 1kW microwave oven will use more energy over a year in "standby" mode keeping the clock running than it will actually cooking meals......

2) Ceiling (and wall / underfloor) insulation. By reducing the amount of heat being lost through your ceiling/walls/floor you drastically reduce the amount of energy required for space heating.

3) Solar Hot Water system. If you have an electric storage hot water system, take a look at your power bill and notice the amount of energy being used on the "off-peak" tariff. That's all being used to heat the water in that tank overnight. Given the available rebates etc this is a worthwhile investment - while the current off peak pricing is low it may not seem worthwhile but electricity distributors in NSW have just had approved an approx 20% increase in pricing for network upgrades and I would be willing to bet that other states are not far behind. Add to that the roll out of Time Of Use metering (TOU) by all retailers which measure your power usage in 30 minute intervals and allows for multiple tariff rates. My suggestion is that you also research "evacuated tube hot water systems" as they more or less eliminate many of the problems of the flat plate systems (e.g. freezing overnight, breaking one or two tubes does not cause leakage or total system failure, no need for glycol mixtures etc) and can be combined with a remote mounted (i.e. ground level) tank if so desired.

4) Photovoltaic system. Yes - even though these are my particular niche they fall at the bottom of the list for energy effectiveness as they are relatively expensive compared to their overall energy output. Same comments as for 3) regarding increasing cost of electricity. Payback period depends on multiple variables - buyback rate from your electricity retailer, your energy usage pattern through the day, system output.

Notice - I say throughout this post energy usage rather than cost - this is because there is more to energy usage than the immediate dollar cost. Other things to consider are carbon dioxide and particulate emissions from coal-fired power stations and the mining / transportation process.

I have no affiliation with the company(s) listed in the earlier / original posts - however in my opinion the parts being specified for the photovoltaic component of the deal are of good quality and are some of the best recognised brands in the field (e.g. SMA inverters, BP / Sunpower / Suntech panels etc). My suggestion would be go for it - I doubt you'll regret it.

If anyone wants a second opinion about systems they've been quoted feel free to ask - I'll need a couple of details about your location and what parts you've been quoted so I can calculate PV system output etc. One important thing to bear in mind with ALL the PV suppliers out there right now is that system outputs are being quoted under "Standard Test Conditions" (STC) i.e. lab conditions, not realistic operating conditions. As a result panel heating, and various other factors come into play and reduce the actual output of your system, (e.g. the oft quoted 1kW domestic system frequently only puts out about 750 - 800 W of instantaneous power even under full sunlight).

IMPORTANT NOTE: The $8000-00 SHCP rebate ends June 30th 2009, if you want to get it you need to send in your pre-approval paperwork quickly - this is a pre-approval only, you are not committed to going ahead with the installation unless there are sneaky terms and conditions by whichever installer you get to provide the system details. Once your application is in however there is around 9 months to actually get the system installed while you can still claim your rebate.

I'm considering solar power, maybe a 2-3kw unit in order to offset the cost of power for my ducted aircon which consumes 5.7kw at max load.

Unless I am misreading the solar guff, it seems that, in NSW, I would be eligible for the gross feed-in tariff of 60 c/kwh whilst consuming power off the grid at 16c/kwh.

Solar Bonus Scheme for NSW | Industry & Investment NSW

This looks a better deal than using my own solar power to supply part of my electrical load (net feed-in).

NSW Solar Bonus Scheme - frequently asked questions | Industry & Investment NSW?

This way, the payback period would appear to be fairly short.

Or am I confused?

Ron, I'm pretty sure you only get paid for your net output. Ie.. if you generate 7kw in a day and use 5kw you get paid the "special" rate on just the 2kw difference. This is how it is in qld, anyway.

The new NSW scheme appears different to the Qld scheme.

Originally Posted by p38arover

I'm considering solar power, maybe a 2-3kw unit in order to offset the cost of power for my ducted aircon which consumes 5.7kw at max load.

Unless I am misreading the solar guff, it seems that, in NSW, I would be eligible for the gross feed-in tariff of 60 c/kwh whilst consuming power off the grid at 16c/kwh.

Solar Bonus Scheme for NSW | Industry & Investment NSW

This looks a better deal than using my own solar power to supply part of my electrical load (net feed-in).

NSW Solar Bonus Scheme - frequently asked questions | Industry & Investment NSW?

This way, the payback period would appear to be fairly short.

Or am I confused?

You lucky man, having a gross feed-in tarriff (I read the link). This means you will be paid the full amount for every kWH your panels produce, something like $1000 p.a. from a 2kW system. Here in SA we still have a net metering tarriff of around 50c per kWH, this is paid for the power your house is returning to the grid, while you are not using it. I think they did that to encourage consumers to run their houses at the lowest consumption possible during the day, otherwise you lose the high feed-in rate.
In either case you have to have an electronic mains meter that can measure which way the juice is flowing.

Originally Posted by p38arover

I'm considering solar power, maybe a 2-3kw unit in order to offset the cost of power for my ducted aircon which consumes 5.7kw at max load.

Unless I am misreading the solar guff, it seems that, in NSW, I would be eligible for the gross feed-in tariff of 60 c/kwh whilst consuming power off the grid at 16c/kwh.

Solar Bonus Scheme for NSW | Industry & Investment NSW

This looks a better deal than using my own solar power to supply part of my electrical load (net feed-in).

NSW Solar Bonus Scheme - frequently asked questions | Industry & Investment NSW?

This way, the payback period would appear to be fairly short.

Or am I confused?

Your reading of this is in line with what a guy at work told me. He's funding his through a Green Loan , while not free, does spread the costs out over a number of years. I believe he's installing a 1.5kW system.

http://www.environment.gov.au/greenl...nes/index.html