Solar Panels Question

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#1861539 9-Sep-2017 20:19

Aredwood:

Jase2985:

most of the hybrid ones i have looked at for battery systems give the same output as the input from the solar panels, so anywhere from about 4.8-6kw. most will allow about up to 7.5kw for a short period (10-60 seconds)

Have you checked if that is for offgrid (blackout mode), or only for on grid? As alot of the battery systems can only output at max capacity while the grid is connected. With offgrid power only being available from a separate connection that is often restricted to a low max output current. And there are even some systems that can't output anything if there is no grid power present. Sure for some use cases this is perfectly fine, but for me on grid output capacity is of no use to me.

Since my power company doesn't support solar PV, I need to get a system that can't physically export power. Both to maintain safety of people working on the power lines network, and to comply with my power companies terms. And my power company (flick electric) is the only one in Auckland AFAIK that offers a peak/offpeak power plan. So if I switch, I loose the cheap offpeak power. Which is especially good at night.

no thats for both on and off grid, you run a separate switchboard for the off grid stuff so when the power goes out it just runs that switchboard while everything else goes dead.

will run the full input/output of the inverter when the mains are off

MikeAqua

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#1862343 11-Sep-2017 13:47

Aredwood:

The 600L of hot water storage capacity will be for multi day storage. With the cylinders plumbed in series (I definitely won't use 600L a day of hot water). The current cylinder and new cylinder is/will be installed downstairs.

I had two cylinders in series in my house in Blenheim, with the first cylinder (no element) heated by wetback/solar-thermal via heat exchangers. Worked really well.

Mike

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#1862344 11-Sep-2017 13:56

Linuxluver:

I've been putting off our own solar installation because I want at least 10kWh of battery storage along with it....and the house isn't built yet that we will install it on. My "perfect" system would be a Tesla (or possibly Monier) solar roof

I was watching a TED interview with Musk yesterday in which he was talking about the solar roof.

Nice looking product (provided you never have to co up on the roof - they look slippery). The roof tiles are made from glass, which had me wondering how much energy goes into manufacturing them?

As I understand it glass is made by floating molten glass onto molten metal. Very energy intensive

They look like they will have a very long life, so they have a long time to payback their embedded energy.

Mike

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#1862350 11-Sep-2017 14:13

I do wonder about how sustainable solar panels are? What happens to them over time and what is the disposal method? Is producing them a resource intensive process?

Seems like Solar won't be cost effective for us unfortunately.

livisun

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#1873627 27-Sep-2017 13:15

Been quoted $8700 for a 3kw solar power system from mercury. My daily consumption is 50kWh, monthly bill is $450 with power shop. Do you think its worth it?

KrazyKid

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#1873630 27-Sep-2017 13:25

It probably comes down to can you use it when generated or if you want it for other reasons (eg security of supply)

1) is someone/something at home using the power during the day as that's when you generate power

2) or can you store the unused power (either batteries of hot water storage etc?)

3) if you can't use it is the 7-8c buy back offered make it economical (probably not) and do you believe the buy backs will continue.

Personally I think a much greener option is to spend the money on an electric car. 80% of our power in NZ is renewables - adding some more solar power does less than reducing C02 by cutting car emissions.

tdgeek

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#1873634 27-Sep-2017 13:29

4) Can you set washing machine, dishwasher to start during a sunny day? And if you can, only use them on sunny days

5) Heatpump on say 18 during parts of a sunny cold day, or on cool in parts of a sunny warm day? That can delay the need later on when solar is off

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#1873671 27-Sep-2017 15:00

KrazyKid:

Personally I think a much greener option is to spend the money on an electric car. 80% of our power in NZ is renewables - adding some more solar power does less than reducing C02 by cutting car emissions.

OTOH, most of our renewable power sources are already heavily committed, so any extra power consumption will mostly be generated from non-renewables. So mostly your electric car will be running on electricity generated by burning fossil fuels.

I guess the ideal is to do both; solar panels and battery storage plus EV.

wellygary

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#1873683 27-Sep-2017 15:50

frankv:

OTOH, most of our renewable power sources are already heavily committed, so any extra power consumption will mostly be generated from non-renewables. So mostly your electric car will be running on electricity generated by burning fossil fuels.

Only if you are charging at Peak times,

NZ's thermals (mostly gas) are more expensive to run than renewables, so they tend to only run at peak,

Charge overnight and you will likely be using baseload Geothermal and Hydro, (or possibly wind, if its blowing)

k14

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#1873798 27-Sep-2017 19:23

wellygary:
frankv:

OTOH, most of our renewable power sources are already heavily committed, so any extra power consumption will mostly be generated from non-renewables. So mostly your electric car will be running on electricity generated by burning fossil fuels.

Only if you are charging at Peak times,

NZ's thermals (mostly gas) are more expensive to run than renewables, so they tend to only run at peak,

Charge overnight and you will likely be using baseload Geothermal and Hydro, (or possibly wind, if its blowing)

Incorrect. Regardless of the time if day you charge, the majority of the time charging your ev will result in more non-renewable generation being used (most likely gas). The counterfactual is either using a petrol or diesel vehicle so in the day you charge the extra generation has to come from the marginal generator, which is most likely to be gas. Even if the gas isn't burnt that day, week or month because hydro supplied your car, some time in the future there will be gas (or even coal) used to make up the defecit cause by charging the EV. In some cases, for instance at the moment when spring inflows to the hydro lakes mean some hydro dams are spilling, then it is definitely not causing extra fossil generation to be used, but this is certainly the exception not the rule.

Overall using an EV definitely emits less CO2 than a fossil fuel vehicle but it is far from "zero emission" like they love to say.

There is another factor to this too. Going forward the next series of new power stations in NZ are most likely to be wind or geothermal. With the uptake of EVs and the increased demand that should arise from this, we should see more new generation built which will over time dilute the gas/coal currently used and further reduce the electricity industry emissions but it will be a very long time before you can truly say using your EV in NZ is completely emission free.

Jase2985

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#1873834 27-Sep-2017 20:35

@livisun:

Been quoted $8700 for a 3kw solar power system from mercury. My daily consumption is 50kWh, monthly bill is $450 with power shop. Do you think its worth it?

unless you know what your base load is and when you use your power IMO its not worth jumping in.

if you start selling power back to the gird the payback period goes up about 3 fold.

we spend about $200-250 per month, max for july was about 40kwh, but our base load is only about .6kwh during the day. so to cover that we would only need a 1kwh system.

you really need to spend some time working things our before you jump in.

Aredwood

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#1873900 27-Sep-2017 22:46

Buying an EV is definitely far better for the environment in NZ than getting solar. As an EV is replacing petrol or diesel usage (0% renewable). So even if you will sometimes be charging from fossil generated power, there is an overall reduction in emissions. While solar is replacing electricity that is already mostly renewable generated. So very little environmental gain for getting solar installed.

Also consider peak demand. Solar doesn't reduce peak demand at all, As peak demand in NZ is on cold winters mornings and evenings, when there is no sun. Charging an EV offpeak uses spare network capacity, So no extra network investment is needed to support your EV charging. As well as using mostly renewable generated power. And adding extra demand late at night when wholesale power prices are low, helps to support renewable generation owners. And helps to encourage more renewable generation to be built.

Also consider that in the future, it is highly likely that either time of use power plans, direct capacity charges, or a mixture of both will become common. This will reduce the returns from owning a solar system. But will allow offpeak EV charging to be cheaper.

Jase2985

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#1873924 28-Sep-2017 05:30

while its great this conversation about EV's and their use of renewable energy, its going a little bit off topic here. its about solar panels and their use

Stan

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#1875016 30-Sep-2017 09:08

What brand of panels/inverter? $8700 is a tad steep for string. You should be able to get a 3kw string around $6800 with reasonable branded stuff.

Jase2985

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#1875106 30-Sep-2017 14:35

@Stan: What brand of panels/inverter? $8700 is a tad steep for string. You should be able to get a 3kw string around $6800 with reasonable branded stuff.

but then what's the instillation cost? or does that include installation?

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