What price does PV solar have to be to make sense?

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#1324375 14-Jun-2015 10:53

raytaylor: It requires a lifestyle change.
In australia and various other countries, power companies are opting not to buy back power any more since they are not required to.

So net metering might not be around for much longer, increasing the payback time.

Personally right now i wouldnt look at anything less than a 8kw system if i was net metering since the panels are so cheap now, and the inverter / grid tie is pretty much the same cost no matter what size you go for. You might as well make back what you can while net metering is still around.

The solar industry needs to be pushing for some drastic law changes
- Mandated net metering option by all power companies
- All new houses of at least 5 bedrooms or more need a solar installation before occupied.
- All new houses need a north facing roof if the pitch is more than 25 degrees so a future home owner can opt for solar if they want to install a system in the future.

Mandated Net metering in NZ would be a silly idea. Why? Because power companies can buy power cheaper on the wholesale market than what net metered solar power would cost them. Which means they would need to increase their prices. This in turn means that people without solar panels would be effectivly paying money to those who do have solar panels. These costs would tend to fall onto mostly poor people. Who already have trouble paying for power.

It won't help the environment. (And would probably end up harming the environment) As peak demand is in mornings and evenings. Yet peak solar output is around midday. So alot of people will be exporting during the day. Meaning their solar power will be displacing renewable generation (0 environmental benefit, owner of renewable power station gets less income) Yet at peak usage times the solar system is unlikely to be producing any usable power. Meaning the power used during peak usage times will be generated using fossil fuels.

Because solar is weather dependent, It is unable to be used as base load generation. This means all solar generation capacity has to be matched by backup generation. Which would usually be fossil fueled generation. Because fossil fuel power plants can quickly have their output ramped up and down. And solar doesn't reduce the amount of lines capacity required either.

Net metering works fine in countries which have most of their electricity generated by fossil fuels or nuclear. But in NZ it would just mean more "peaking" fossil fuel plants would need to be built.

Stan

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#1324379 14-Jun-2015 11:16

richms: The install cost needs to get under control.

Typical problem of high NZ labour costs and really expensive mounting systems dwarf the costs of the panels. Hell, the panels could be free and it would still cost too much to install in NZ.

Installation is not that expensive. The unit that I quoted above install cost (built in to the price) is 550+gst/council fees

Sorry I should have mentioned the size of the $5999 unit is a 1.5kw unit (6 panels)

Kiwibank run a scheme where they contribute $2000 towards your unit so with that the payback time would come down to between 5-10 years.

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#1324509 14-Jun-2015 17:32

Aredwood:

Mandated Net metering in NZ would be a silly idea. Why? Because power companies can buy power cheaper on the wholesale market than what net metered solar power would cost them. Which means they would need to increase their prices. This in turn means that people without solar panels would be effectivly paying money to those who do have solar panels. These costs would tend to fall onto mostly poor people. Who already have trouble paying for power.

It won't help the environment. (And would probably end up harming the environment) As peak demand is in mornings and evenings. Yet peak solar output is around midday. So alot of people will be exporting during the day. Meaning their solar power will be displacing renewable generation (0 environmental benefit, owner of renewable power station gets less income) Yet at peak usage times the solar system is unlikely to be producing any usable power. Meaning the power used during peak usage times will be generated using fossil fuels.

Because solar is weather dependent, It is unable to be used as base load generation. This means all solar generation capacity has to be matched by backup generation. Which would usually be fossil fueled generation. Because fossil fuel power plants can quickly have their output ramped up and down. And solar doesn't reduce the amount of lines capacity required either.

Net metering works fine in countries which have most of their electricity generated by fossil fuels or nuclear. But in NZ it would just mean more "peaking" fossil fuel plants would need to be built.

I still disagree

Dishwashers, washing machines, water heaters etc can be programmed to run during the day taking load off the evening.
This is because the retailer only needs to buy the power at a commercial rate. You become highly motivated to change your electricity usage patterns if its cheaper to use the power that you self-generate vs what you buy.

Costs of maintaining the lines still need to be accepted, usually by an increase in the ICP daily connection charge for a net metering customer which allows for the recovery of the lost local lines and transpower fees.

And remember its simply offsetting some of the water usage of hydro during the day. When there is more water in the lakes for evening usage we can become less dependant on fossil fuel to top up the difference.

Hydro can ramp up or down quickly too
Coal may take an hour to come online, where as hydro can be switched on in seconds.

Watch this video.
Ignore the fact they are talking about pumped storage - its already in the top lake because it wasnt used during the day.
https://youtu.be/DUibNlJseac?t=9m30s
Start at 9 mins 30 seconds for approx 2 minutes.

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billgates

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#1324517 14-Jun-2015 18:03

Is it worth getting Solar installed for a new house build? 4.32kW LG Mono X Black system with enphase micro inverters installed for $17k. Is 4.32kW guaranteed or close to it production for at least 3 ~ 4 hours per day on a good afternoon. Thread is interesting because ROI for this system could take many years.and by then new tech will be much cheaper with battery storage options. My bill from flick shows that I never seem to exceed over 3 units in any given hour including peak.

Do whatever you want to do man.

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#1324520 14-Jun-2015 18:16

billgates: Is it worth getting Solar installed for a new house build? 4.32kW LG Mono X Black system with enphase micro inverters installed for $17k. Is 4.32kW guaranteed or close to it production for at least 3 ~ 4 hours per day on a good afternoon. Thread is interesting because ROI for this system could take many years.and by then new tech will be much cheaper with battery storage options. My bill from flick shows that I never seem to exceed over 3 units in any given hour including peak.

4.32kW is on a clear day in the middle of summer, basically. During winter you're looking at at least half the generation of in summer on average. If it's a miserable rainy day you can get pretty close to nothing - though ambient light does a little bit. Not to throw you off the idea, but this has been my observations in a house with solar.

We've got a 3.2kW system that was installed last November and has had an average of 12.73kWh per day since then. During summer you can get mid 20s on a good day, but during winter a good day is around 10kWh. Here's the graphs for those interested. The sharp dropoff today is when it got cloudy I believe - otherwise it'd be a bit more of a smooth (but still fairly sharp) descent.

Here's the daily generation since it was installed:

mattwnz

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#1324523 14-Jun-2015 18:21

You say you work for a retailer looking to get into it. What typ eof products do you already sell, and do they complement this? There must be pretty good margins in it for retailers, as some of the retailers who had no association with this sort of industry have started selling them. I think it will be at an affordable level when mainstream people start buying them, similar to the number currently buying heatpumps. If you have good mains supply, I don't see any benefit in them.

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#1324528 14-Jun-2015 18:49

Stan: Full disclosure not looking to advertise but I work for a retailer that is looking at getting into PV solar...

What would make you purchase a system is it payback time, yield or geeky interest?

NZ has relatively low market penetration why do you think this is?

Our entry level system would be using canadian solar polycrystalline panels and Enphase micro inverters fully installed system would cost $5999.

Really interested in general feedback...

I see solar as being supplementary (I have zero interest in feeding back to the grid, as I will always consume more than I generate), and PV only makes sense to me as part of a much larger system. What would seal the deal for me is a reasonably priced solution, efficiently combining solar (or other power sources), battery chargers, inverter, generator controls, and an automatic transfer switch. I require battery backup only to handle the transition to generator.

When I looked in to it a few years ago, such systems cost several thousand dollars by themselves, and that was only for the entry level model.

JimmyH

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#1324538 14-Jun-2015 19:13

I'm not that interested in rules requiring power companies, homeowners or home-builders to mandatorily do anything. And I certainly don't think the government should subsidise installs.

Personally, if have a straightforward view on this. I would install solar if, and only if, the financials make sense. By sense, I mean given my usage pattern I would expect an internal rate of return on the capital outlaid of at least 11% (pre-tax equivalent, or 7.4% post-tax), to allow for risk and the opportunity cost of money. And it isn't close to there yet. Otherwise, I would be better off just paying down the mortgage.

If it was a line-call I might be tempted by a system if it had a battery (like Elon Musk's) included that would let me isolate my house electrics from the grid with a switch and run minimal essential systems (fridge, freezer, laptop/internet, some lights, and a radio or TV) for 24-48 hours in an emergency, as a disaster preparation. In fact, given my usage pattern a decent battery is probably essential to getting the numbers over the line - so I can save up surplus power during the day and take the peak off my evening usage.

Getting me to buy is simple, just show me credible financial numbers that work. Until you can, don't bother pitching a system at me as I won't be interested.

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#1324561 14-Jun-2015 19:28

I looked at a 7kWh grid tied system sometime back, the payback was looking to be a very optimistic 12 years but the problem I had was that there is no guarantee that any retailer will buy back at a decent guaranteed rate let alone at the same rate they retaill to me. Time the govt did something about that

The sheer uncertainty around the ROI [which includes what I can sell back at] makes it unattractive to me, at least back when I looked. Whether battery advances [technically and commercially] change that time will tell

Aredwood

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#1324626 14-Jun-2015 21:15

raytaylor:
Dishwashers, washing machines, water heaters etc can be programmed to run during the day taking load off the evening.
This is because the retailer only needs to buy the power at a commercial rate. You become highly motivated to change your electricity usage patterns if its cheaper to use the power that you self-generate vs what you buy.

.

Sorry im confused on what exactly you are proposing. Your first post you said you wanted Net metering.

Yet above you are saying that the retailer only needs to buy power at a commercial rate. - But if they are paying a lesser rate for exported power then that is not net metering.

Net metering is where the export rate and the import rate are the same. So you are only paying for the difference between what you use and what you export. This means you have zero incentive to try and directly use your generation. Due to the power company paying you at your retail rate for exported power.

raytaylor

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#1324646 14-Jun-2015 22:01

Ahh that would be why you are confused.
I have used the wrong word. I mean to say buy-back or something like that.

Ray Taylor

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#1324665 14-Jun-2015 23:23

I would have thouhght it was far more efficient in materials, and labour, to have commerical solar cells installed in certain areas of NZ which get good all day sun, rather than have them installed on each house. I also beleive at the moment, wind energy , and hydro have a better pay off on ROI. But the RMA makes such schemes difficult now.

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#1324681 15-Jun-2015 03:34

The thing going against home solar is that utility scale PV is actually much cheaper per KWh.

Net-metering is a non-starter for me, given that grid-tie residential solar (import/export) still 'touches' the whole power grid. If the exporting price is set to the purchase price then it would have to include at the minimum deductions for the local lines, retailer profit etc, largely leaving the wholesale price plus the high voltage network levy. Solar users will end up becoming low users (import) and power companies are going to recoup their savings by upping the per unit charges and fixed costs paid by these low users.

Personally I am opposed to any policy that results in a transfer of money from non-solar households to solar households, because I believe it will impact more on the most vulnerable members of our society. That is, the poor and renters who cannot afford to buy property. If there are subsidies I would rather they go to energy efficiency than solar as there is plenty of research showing it is the most cost effective investment [1].

k1wi

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#1324682 15-Jun-2015 03:44

k14

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#1324736 15-Jun-2015 08:55

raytaylor:
Hydro can ramp up or down quickly too
Coal may take an hour to come online, where as hydro can be switched on in seconds.

Not quite, coal can take up to 48 hours to come on (depending on how cold the boiler was before start sequence began). A hydro machine can go from 0MW to full capacity in around 2-3 minutes.

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