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[Phil Squire]

Ahoy energy people

Does anyone have data files (or something like that) for typical profiles of household energy use? AT Sust Trust we’re trying to find some typical sets to use in our PV analysis. Basically the outcome would be to determine for a certain kind of household how much solar elec they are likely to export or use on site.

There will be a range of different profiles for families who work, elderly, people at home etc. And of course different seasons. Any help greatly appreciated.

Cheers, Phil

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[Norman Smith]

Hi Phil, Ten years of HEEP data could be a good place to start even though the research was concluded a while back – http://www.energymonitor.org.nz/heep-table-of-contents – also drilling down into their hot water study. http://www.energymonitor.org.nz/heep-final-hotwater-contents

Cheers, Norman

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[Scott Willis]

Hi Phil,
I do have some data that I should be pulling together in any case for BRCT, but in the meantime, rule of thumb we have is that a low user household should aim for approx. 2kW array, while a high user household should aim for a 4kW array.
There are many variables to consider:
– Is anyone home during the day? If so, it enables a higher percentage of solar electricity to be used when it is being generated, offsetting any bought off the grid.
– Will the homeowner also incorporate timers and other bits of kit to move load around?
– Is the homeowner willing to make changes to their lifestyle to make the most of the solar? (the answer to this is always yes actually – everyone does it when they see the benefits it has).
– What space do they have for solar? Roof space and aspect may be a limiting element, but some homes have space to ground mount or sheds, garages, etc.

FYI, in our community we range from about 38% to 58% (roughly) of solar electricity generated being used on-site at the household. I know in our own house we are over 50%, but that’s because we pay attention to appliances and my wife works from home.

One of the biggest motivators people have at present comes from the market: there is no point exporting more that 5kWh of solar electricity per day, so unless you are rich and green and just want to do good for the environment, you should aim to build a system that will match, roughly, your demand and try to keep within the 5kWh export threshold (Meridian). However I should point out that the market is a political construct and if there is a Green/Labour government after the election we are likely to see greater market certainty and ease for small scale generators.

So I guess what I’m saying is, the infrastructure is costly and a fixed asset, but the market is mutable – so don’t limit options. Strategically, this means from my perspective: build to match today’s consumption, prepare to clip on more when conditions improve. This involves consideration of how to add in extra ‘strings’, selection (and life-span) of inverter or panels with micro-inverters, etc. I think I’m making it sound more complicated than it really is…

What we all have to confront in NZ is an electricity market that doesn’t really want distributed solar and so what is happening is that solar installations and homes with solar are increasingly working organically to grow the percentage of solar electricity used within the home – either through staggering appliance draw, or through adding in storage as well (minor as yet outside of the Vector zone, but becoming much simpler).

When we get our information into a sensible format I’ll provide it here.
Cheers
Scott

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[Norman Smith]

Hi Scott, Phil et al,

As some of you know a colleague Andrew Smith and I have developed an NPV-driven spreadsheet which take a hard (some would say brutal) look at PV. This takes into account a myriad of variables which seems to interface pretty well with and generally complement Scott’s perspective.

To me the bigger issue is this; there is a lot going on behind the scenes including a new inter-department working group of Government ageencies looking at PV, EECA internal papers which outline their non-supportive position, not to mention the Electrical Network Assn’s current discussion about development of in:out charges for PV in the interests of equity.

At a time when there is aggregation and major change and rationalisation taking place in the PV industry and with a number of ‘game changing’ financial and technology-driven offerings about to come onto the market from the private sector (e.g. PV to hot water only via a new kind of inverter) and the commoditisation of PV such as the Harrison’s model why is there no serious collaboration betwen CEN members?

At the risk of ruffling feathers has anybody heard about any of this stuff which I come across in my PV work with lines companies, councils and others?

A number of CEN members are now involved with PV or thinking about it and from my conversations its seems everyone is doing their own thing apart from occasional exchanges such as this through the Hub.

I believe the best and perhaps only way for you to survive/grow in PV over the next two years is to get serious about creating some kind of collective entity which pools knowledge and resources and buying power and networks at every level.

Food for thought in Wellington next week?

Cheers, Norman

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[Phil Squire]

Yes, well said Norman (and thanks for the info Scott). I’ve been doing some digging this week on volume buying through Yingli, Mitsubishi, Canadian Solar, Renesola etc. We’ve also had some conversations between some members on business models recently and “franchising” the more successful ones, but yes a more cohesive approach would yield bigger results.

As you know the work we’re doing here at ST on larger arrays is in swing and could provide a solid income-generation model for developing larger arrays (1MW or more) that is owned by CEN (though not sure if the IP can be protected – would be more of first-mover basis).

I’ll bring it up with the Managing Committee next week.

Cheers, Phil

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[Scott Willis]

Hi Norman and all,
Firstly, thank you Norman for the challenge. I certainly appreciated the work you’ve previously done on the economics of PV, and as you know I am a proponent of analyses that take into account the change in energy culture that accompanies PV uptake (and improves the economics incidentally).
The Smart Grid Forum is up and running, and it incorporates non-government participants as well as those from govt. agencies. In our own neck of the woods we are trying to get practical things happening on the ground, with trials of smart grid tech happening in the Blueskin space. I am certainly following the SGF work and receive minutes and updates.

BUT I would value CEN’s role in solar increasing – in the first instance it would be more a ‘state of play’ in order to understand the very chaotic solar space, and perhaps continuing the hub, ‘collective entity’ if you like. And EnergyShare (http://www.energyshare.co.nz/) is a practical attempt at this already. The real challenge for us here (in Blueskin) to do more with our experience in solar is time, people and resourcing – we can’t see the wood for the trees as it were, and solar for us isn’t a social business, it is just part of the community service (information) that we provide, while we work on the main project and subsidiary work. From my own experience in PV at our own home, it felt as if putting up solar at home was as complicated as putting up community wind! (That said, the 2kW home array is up, the 2.55MW community wind farm is still in process…). What would it take for CEN to take a more active role in solar?

One of the big issues any general approach to solar will face is the great diversity of situations and arrangements, from inner city solar, to distributed collectives, to network led investment, to rural ‘viral’ solar creep…

Cheers, Scott

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[Scott Willis]

Hi Phil,
Oops, I was posting when you posted… ST’s work is exciting, and I’m keen to see where you get to as I’m convinced that early upscaling will come from either energy literate or socially/environmentally motivate partners – the CEN ownership of generation is an exciting idea and one that is very timely!
Cheers
Scott

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[Norman Smith]

Thanks to you both for accepting the challenge in the spirit it was laid down! Energyshare is an interesting mixed model, I had a close look at it recently wearing my Akina hat.
Norman

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