By Gareth Vaughan
As Auckland debates whether its future should be as a more compact, high rise city or as one that continues to sprawl outwards, how energy is sourced and consumed ought to be an important part of the discussion.
So says Nirmal Nair, a senior lecturer at the University of Auckland's Department of Electrical and Computer Engineering. Nair, along with colleagues from the university's architecture department, Hugh Byrd and Anna Ho, and another from the business school, Basil Sharp, is the author of a report entitled Measuring the solar potential of a city and its implications on energy policy. They used Auckland as their case study.
In a Double Shot interview Nair told interest.co.nz a key question for him was whether Auckland could develop some level of energy self sufficiency. Looking out 30-50 years, Auckland needs an energy plan.
"If you look at Auckland as a city, and look at what its energy consumption is, be it electricity, be it gas, be it the petroleum products to run our cars, we are importing all of them," said Nair.
"That is the reality so there in lies the question; Can we be a little bit of a producer? And solar sprang out neatly and clearly."
From both a resilience aspect, and from a growth perspective, energy should definitely be part of the equation, Nair says.
The Auckland Council has been consulting on its Unitary Plan that sets out the aim of absorbing the majority of Auckland's population growth in a more compact, high density manner over the next 30 years. However, the Government has indicated a desire to see more greenfields land opened up for development around Auckland's fringes. See all our stories related to the Unitary Plan here.
Byrd, Sharp and Nair's study concludes that; "Low dense suburbia is not only the most efficient collector of solar energy but that enough excess electricity can be generated to power daily transport needs of suburbia and also contribute to peak daytime electrical loads in the city centre."
"This challenges conventional thinking that suburbia is energy inefficient. While a compact city may be more efficient for the internal combustion engine vehicles, a dispersed city is more efficient when distributed generation solar power is the main energy source and electric vehicles are the means of transport."
Nair makes it clear , however, that he's not necessarily advocating for greenfields development over higher density living. Rather, he wants to see energy as part of the debate.
In terms of solar power potential, Auckland stacks up well compared with cities overseas.
"We were doing international benchmarks," said Nair. "We were looking at Madrid where there were a lot of investments into clean technologies like solar, cities in Germany, LA where there were incentives like (subsidised) feed-in tariffs to encourage solar. In all these places we found Auckland had one of the best weather patterns from the point of solar potential. So it stacks up pretty well compared internationally."
Their study looked at a cross section of Auckland from the Central Business District out about 10 kilometres through Mt Eden and Sandringham to New Lynn.
They also looked at the possibility of using solar energy generated on rooftops to power electric cars. Although acknowledging the development of electric cars to a point where they're feasible for mass, mainstream use, was a "big unknown," Nair said over the medium to long-term, he and his fellow authors are optimistic.
"When we're talking about the 10-year timeframe, or the 20-year timeframe, or even a generational timeframe - the electric vehicle - definitely we should be looking at this from that aspirational aspect as well," Nair said.
*The charts and graphic below come from Nair, Byrd, Ho and Sharp's study.
61 Comments
Great article.
Solar-electric (PV) is now cheaper than solar-water, and local is the way to go. Have to remember that we get 1 kw landing on a perpendicular square meter,. Water is 80% efficient, PV is currently 15%, so you need more area.
The best use first, is PV straight to hot water; it dodges the need for grid-tied (phase-tied) connections, but relieves much of the load from the grid, and from your pocket. At circa $1 a watt ($1000 kw) it's viable right now.
Only good for north-facing and unshaded aspect, of course. Shold have been written into all our district plans 30 years ago. Meridian's rep at the 'Valuing Nature Conf acknowledged that local solar was the way forward. Being as how that competes with their business model, they'll have to get into the game.
O'seas they're statring to rent sun-facing roof space....... game on. Some of us, of course, are 10 years down the solar off-grid track, and have been powering our electric bikes for a while. :) Good to see such an artice - kudos to GV
Some assumptions.
a) EVs and more importantly their batteries will be affordable and common place. At even 1/2 the present price I cant see EV's being a common transport for most ppl...not unless their money is freed up from other things like housing debt, then 35~40k for an EV becomes affordable.Otherwise they and the poor will need public transport...but trolley buses might work fine, its the mix / ratios thats going to prove interesting to work out, lots of iteration.
b) What the report is suggesting is using surburbian housing roofs as a platform for PVs, yet half or more of such roof areas face the wrong way....so we could simply have a simple scafold with PVs on it at the optimised angle further out and live more densly. As well as a green belt a solar belt.
PVs are looking to be the in-thing, can but hope the EU and US blocks all the cheap chinese imports and it all comes here....Germany of the south pacific. If nothing else doing stuff like working from home starts to look more and more economic. No energy used to commute and "free" electrical power at home, swapping a transport energy for a static energy use is always good.
A really interesting piece though.
Hrmm, biggest thing is the timeline they see....20 or 30 years away....
regards
Yes, in a recent BBC interview with Steven Chu ex energy advisor to the White House was saying that in the future the power generators and distributors will need to change their business models to distributed processing by installing PV on consumers roof-space and deep-cycle batteries in their garages, at no cost to the consumer and offering lower tariffs in exchange thus reducing excess loadings and better managing peak load production. It's happening.
Read recently of some new zealand consumers using $3,000 per year in power. Be surprising if the average nz household consumed $3,000 a year in petrol. Would seem better value to cosume the PV power for domestic consumption. But not until all the SOE's are flogged off. Of course.
The writing is on the wall. You can see why govt is keen to flog the power units.
Over supply of oil means price could halve to approx $50 per barrell according to international expert - so that should keep our inflation rate well down
Do you have any papers / URLs on this? There is some but much of it is biased from the power boards who are losing income...
Simply that may not be so bad, right now we are simply talking about a reversal of the present power. 3.5kw units is 7 amps into the system, when in peak times we could be drawing 20 or 30amps. The UK and Germany do a lot of this...though note he's saying its somethign for the future and not tomorrow, so as we upgarde and replace we put in "smart bits" as needed.
regards
Queensland is a good example. In the recent years, the state govt did a massive push for solar panels installation in private homes. From memory they achieved about 20% of all homes. Until last year, they promised to buy back at 44c/KW while the selling rate for domestic is between 20-24c/kWh.
It’s now being scaled back to 8c/kWh. One of reasons is the network can not cope with two way traffic, it was built to deliver power from sub-station to home not the other way round.
Hi, yes thats correct, to a point. 44cents was silly, what should have been was tarrif parity and guaranteed for a long time ie 15 years to get a return, but on a first come first served basis, ie once the capacity on that leg was met no one else could feed in. Then there should have been upgardes to the system, of course there is no incentive for that. The above report / work makes it clear, in the future 2 way feed is what we will need to have. thats the problem we face really, vested interests not wanting to damage their profits as opposed to making a resilient service to support our economy.
regards
"Why should we" that'll be the answer from electricity companies. Interestingly, there is a slight demands here in QLD to install solar generator to storage system (i.e charging a bank of deep cycle batteries) but the cost is still between 10-20K.
Wonder if Mr Rudd will look at some incentives..! I would go for it if it’s under 10K.
Yep, in a way I can understand that and thats part of the problem. Power and water are utilities that are there to support the economy and not be a profit centre. So their job is to supply power cheaply over the long term and be there 24/7/365....then ppl and businesses can run safely and profitably.
Batteries make no sense. But there is a US tech coming that looks promising, its very cheap and long lasting....
regards
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Cheers.
after the kobe earth quake electric cars supplied power for days, i have heard they started to put plugs on them afterward. In australia its a growing trick now for people to plug the car in and feed back to the house at night. Peak oil yeah right. buy share in power companies i think not. watt price is so low a seachange is comming. great the uni spotted the obvious.
I was reading, earlier in the month, about Stella- a solar car that generates more power than it takes to drive it.
http://gizmodo.com/the-solar-powered-car-clark-griswold-would-drive-678…
Some points to note.
1. Don't expect any subsidies from "Green Clean NZ" with National in power. They have TUBBIN and are saying that "we are already world leaders in renewables so we don't care; we are happy to burn coal/oil/gas..."?
2. The grid is meant to push LOTS of electricity from BIG generators up the "tree" to the leaves... SO if you try to push too much power back UP from the leaves to the branches "the wrong way" then you end up having problems.. I read that some part so Oz are limiting new on-grid systems so.... get in there quick.... I did try to point this out to CERA at the beginning of the ChCh Eq re-build so they coulkd plan for this (i.e. bigger "pipes") but got the usual "We just don't care" response.
I stil do have 10kw system - on Grid as they haven't found an Earth #2 yet... and as for ROI; it's not bad - but was never the real reason I did it!
Enjoy.
I already have a 4KW Solar PV system on my bugalow roof in Mt Eden.
Then, Meridian changed the rules and will only rebate back 50% of the price of power I produce over 5kwh per day.
So i pay them 30c per kwh, and they buy mine back at 15c. Obviously my power isn't as sexy, trendy, <insert marketing word here> as theirs.
Apparantly this is because Vector clips the ticket both ways for using the lines network, so they bite 15c per kwh to deliver my power and 15c per kwh to deliver it for me to someone else.
Unfortunately, I'm sure that rate accounts for a prorated cost of a large scale distribution network accross the country including large transmission towers etc.
Doesn't seem to matter that my power probably gets used by the Cafe around the corner to power it's expresso machine, I still pay through the nose.
Upshot of all this is that Solar PV did become economical briefly, but due to the current rebate structure and no sign of any form of positive incentive from govt etc, does now not return anything close to what it would need to justify the original capital outlay.
Why are you paying 30cents?
and yes this needs to change, anything produced locally is used locally and saves on transmission losses. One thing the Green's could legislate on, parity of infeed ie if you are charges 23cents you get paid 23cents, the coimpany makes on the lack of losses.
regards
Your 30 cents / kwh equates roughly 50-50 to an energy charge plus a lines charge which is a fixed cost.
It is perfectly rational while you remain connected to the grid that you only are reimbursed for the energy you provide. Your energy uses the grid to deliver the power you generate - exactly as you consume energy of an evening - so there should be no credit for this.
The buyback scheme in QLD has been a predictable disaster as by paying the full tariff, they in effect left the fixed line costs to be payed by those without solar. This lead more and more to install solar - leaving fixed costs to be payed over an ever smaller customer base.
Typical political and totally predictable stupidity.
It makes no sense to use PV to heat water. First rule of thermodynamics is to restrict energy transformations . Far better to mount solar water heaters on the roof. Heating water is generally the largest household load.
There is no logic for a city to be self sufficient in anything including power. Economics says it should be sourced at the lowest economic risked cost and if that is from geothermal and hydro delivered over a secure grid so be it.
JB - there is no logic in economics. Not in an energy descent, there's not. It might be a numerical system capable of tracking the descent, but the rules applicable in the growth period do not apply.
That said, while things hang together, PV is now 'cheaper' than solar-water, and by a widening margin. No leaks, no roof-weight, no pumps. More area is the only downside.
PV to hot-water, not grid-tied, avoids the Queensland problem (largely a grid-balancing on-the-bike thing, when the sun burst forth) by using the cumulative capacitance of the HW cylinders.
I suspect you know that. Do I smell an older mind or a vested interest? Both?
And look at this - coming to a place near you
http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10898450
http://www.nzherald.co.nz/politics/news/article.cfm?c_id=280&objectid=10898242
When Auckland starts charging tolls on the motorways anyone with a few clues will start using the non-motorways and residential streets - and the suburban residents will complain - and the councils will then block off access to the urban through-roads and force channel motorists back on to the motorways - and then muggins-you will end up having to go down to the nearest motorway on-ramp, get on the motorway, head up to the nearest off-ramp, do a U-turn back towards your place - just to get to the nearest milk-bar or macdonalds or liquor-outlet.
Have been told rightly or wrongly that relatively practical and economical home batteries for solar PV are not too many years away, and will be easily enough added to a home solar system. If others know whether this is truely likely or not, I would be interested, as have just been quoted for a 10k system, and the ROI case is borderline, but would be a definite go if batteries were not too far away.
That would presumably fix the system of the lines not really being designed for two way traffic; and also fix the power companies altering their buy and sell prices. If nearly all the power produced is used in the home anyway, then the prices are somewhat immaterial.
SL - 10k for what? Batteries? I built my whole system, genny, panels, pelton wheel, wiring, switches, LED's, the works, for $4,200, in 2005. Reckon it'd be cheaper now. It's not the lines, it's the balancing of the grid centrally, is the issue, Your HW cylinder if your first battery.
Pdk, There is a significant premium for those of us who don't really know what we are doing. Approx $30k for a 10kw pv system installed with inverter. Batteries not included. German panels. Panels need to be on a flat roof with angled supports to face the sun and weights to hold them down. Pays back in 7 years at current prices and probably slightly optimistic production numbers.
Good on you for looking. I'm assuming you're on-grid? Try looking at a dual element (you can get them in a single standard fitting) for your HW cylinder, and put the conventional grid to one (it'll be there now) and PV to the other. Look perhaps to put the overload into a water storage/radiator system (if you get cold / live south). 10kw? I got by on 50watts for the first 5 years, and a mere 200 now, plus pelton (70-ish watts, 24/7). What do/would you do with it all?
I don't think in terms of 'payback' too much; I reckon the fiscal system has to crash, and digital wealth may well go with it. Better an energy-source on the roof, etc.... The other way is the 'peak/descent/commons line of thought; we will use the oil till it's gone, then it won't be available. (and we won't sequestrate because we can't afford it now, and that will only get worse). The way to use it later, is to own something made while it was available, which will still function afterwards. PV ticks that box in spades.
Also, prices for energy are going up, not down, relative to incomes. That will impact the upper end of the First World last of all, but influence them it will.
Just wait a little, things are a'changing, fast. Guy Waipara of Meridian, acknowledged last week that local solar was where it is going, and I know of several folk eyeing up the new paradigm. PV and LED will scale, and become the only game in town. Wind will fade, and we'll never see a major new hydro scheme (minor and micro, yes). Interesting times. Lotta venture capital went into renewables; they all knew that whoever hit the jackpot would cream
Thanks for the reply. Yes am on grid. I'm not actually too fussed on the payback either, but would like it to make some commercial sense. I suspect PDK, you'd be horrified at my house, and its power useage; and I wouldn't find it easy at all to live in yours. 50 watts would barely light one of my rooms.
Will ask the questions re splitting for hot water and PV.
The main hurdle will be the wife and her view of the house aesthetics; albeit the system will I think be largely hidden away on top of the roof.
Waiting may win, although I suspect significant costs are actually in installation rather than the gear; and am not sure the installation costs will come down. I also don't know if such systems add any value to a house's resale value; but again, don't care too much. If though, you plan to sell the house soonish it does matter. Payback then means getting on with it is probably better. The main reason for waiting would be if the panels were going to become a lot more productive in terms of outputin the near term. You may know if that is likely.
To Steven's question, yes they have a 10 year warranty.
Whats the warrantee? 10 years? is this a battery system? your big expense and outlay in the future will be battery replacement....that can be silly money like 12cents a kwh, I cant see that they are worth it. Really selling to the power company or heating hot water if the power company pay poorly seem the way to aim.
regards
The pelton wheel is near 6 amps @ 12 volts. We could live on it with no solar, but in drought times we've seen the water dry up completely twice in 20 years, and to a trickle often.
If it dries up, it has to be because of excess sun, so solar is the symbiotic partner to micro-hydro. When the sun shines and the wheel is chugging along full-output, we just have extra - goes to a dump-load (soom to be water-heating).
Batteries are the weakness and I suspect pretty much will be. However you dont need batteries when you can sell excess into the grid and buy it back when needed.
If you can get a warrantee longer than the payback and have the capital it would seem worth considering. ie 10 year warrantee 7 year payback....the killer is if you are also paying interest on the loan say 7%....hence I have not bothered yet as thats my only avenue today.
regards
the building i am in sunshine coast qld has only 5kw syatem as thats the limit they will buy back. but one of the interesting things was mostly well off people could afford to get the systems & the subsidie . they are the one selling it during the day and useing the car at night so the power companies really miss out. So the poor cant afford the sytems are left paying the price. they are now reducing the carbon tax from (average house hold) $2000 a year to $1850 . If your got your own system i wonder what you pay?? I know lets bring in a subsidie in NZ ( sorry)
Hence why I dont agree with such a profitable payback really the poor pay it. Buying at retail or thereabouts is still saving the energy company considerable transmission losses. I'd like to see some honest numbers myself... selling at 15cents when buying it at 23cents doesnt seem to outlandish...8cents, no.
5kw isnt a bad size, thats still 20amps, you should be able to run most of your house on that.
regards
PDK and Morley are on to it.
The cost of PV panels has become close to negligible compared to the cost of battery storage. And with the cost of storing energy in the form of hot water about 1/20th that of storing it in a battery, the numbers work out very well for PV to hot water.
I have a PV system on a commercial building that has no batteries at all. The PVs drive the LED lights, heaters in winter and a few other bits and pieces. All excess energy gets dumped into the HWC which has 2 elements, one driven by the PVs and the other a mains backup.
The system works brilliantly, and because every unit of energy produced is used to reduce the power bill, the payback works out to around 3 years.
Just to get this clear, power from PV goes to electic use first, then hot water heating, then the grid? So during the day, you are probably still selling back to the grid and still using power from the grid at night?
I see that this will save you on the transmission costs while heating hot water but you will still need the grid to provide the balance during non-sunlight hours. Would adding a battery array just big enough to run lights/appliances at night be economical?
There is no grid tie, the PV system runs semi-independent of the grid. The LED lighting system runs on PV but is topped up by the grid via diodes when the PVs cannot supply enough power. The HWC has two elemets, one running off PVs and the other off the grid.
The system is ideal for commercial buildings because there's nobody there at night. Residential will always be more difficult because that's were people are at night.
The biggest problem with batteries is that they are so expensive that it is virtually impossible to pay them off with the energy they can store in their lifetime. A $1000 battery can stored about 50c worth of energy, it needs to be fully charged and discharged 2000 times before it's paid for itself. And by then it needs to be replaced because it's worked so hard. A $1000 HWC, on the other hand, can store about $4 worth of energy and will easily last 25 years.
Hey guys let's be clear here it's not the power generators/retailers at fault it's the lines companies - Transpower and Vector in Auckland - that are the bad guys in the on-grid pricing and lack of ability to support high levels of domestic power generation.
I heard a few years ago from one of the generators that Transpower was already struggling with the variable supply from the growing number of wind farms - they just cannot manage a grid without guarenteed inputs that they get from thermal, hydro and geothermal. It breaks the 30 minute game of poker that they run all day every day.
Yep wind is a problem, thats known. One interesting solution is a container full of cheap batteries (new design) that smooths that. The design is quite advanced so maybe 2 years off. Sure they cannot support it, however they are going to have to....sooner than they realise maybe.
regards
OMGWTF - no ripoff. Quite the opposite.
Both quoted sources are finite, neither cover the costs of externaltities (mostly disposal, in both cases).
The ripoff is of future generations who will not have the energy available, but will have to address the resultant pollution (CO2 and radioactive waste) as well. That's theft, fraud, hell, it's both. From their point of view, what should the cost be?
Time some folk took responsibility.
Im not aware any nuclear plant has to cover the the cost of the 100000 odd years its waste will be deadly. So really that 10cents should be way higher. Coal is fighting a battle with copious cheap shale gas in the US, which might be ended in a few years, then the prices will rise. I dont see how you can take something as being cheap today and be unwilling to consider just where the prices will go a few years out.
NZ's prices are I think a construct of inflated assets in a badly constructed market used to the advantage of the Pollies....both parties of course....Labour were no better happliy taking the dividends.....maybe voting Green isnt such a bad idea in this respect.
In saying that of course making something expensive encourages switching to alternatives and reduces wastage...its how these excess funds get used is most important....ie reducing cosst and not spending on more things not needed.
I suspect we'll be cursing the Pollies something awful inside a few years when we realise how much time they have wasted.....
regards
Looks like plenty of improvements in solar and batteries coming up thanks to nanotechnology.
Such panels, which have the potential to surpass any substance other than reactor-grade uranium in terms of energy produced per pound of material, could be made from stacked sheets of one-molecule-thick materials such as graphene or molybdenum disulfide.
Antifreeze, Cheap Materials May Lead To Low Cost Solar Energy
A process combining some comparatively cheap materials and the same antifreeze that keeps an automobile radiator from freezing in cold weather may be the key to making solar cells that cost less and avoid toxic compounds, while further expanding the use of solar energy...
...cook up the solar cells in a microwave oven similar to the one in most kitchens...is easily scaled up for mass production at industrial levels.
This technology has a promising field of application in the manufacture of batteries with higher energy density. Faced with ion-lithium batteries, the batteries based on lithium-sulphur provide a three times higher autonomy, but without increasing their size and weight, and with a lower cost. Solar cells are also presented as an attractive alternative to reduce production costs, improving aspects such as stability and durability to make them more profitable, and turning photovoltaic electricity into a safe, clean and sustainable choice.
Discrete PV panels are soooo last century.
They suffer from a number of regulatory issues as well:
- sparky needed to hook 'em up
- building consent for the whole install
- which may need engineer input if coastal, TC3, yada yada.
- if yer rilly lucky, a resource consent opening yez up to the Nimby's living over the fence
- terribly visible, so little chance of going under the radar/running dark and deep
The solution?
Solar generation built into the building envelope itself. Downside: cannot adjust or even pick angles (unless a new build). Upside - dodge most or all of the above - 's little different to a coat of paint.
Sources: Nanosolar, and I'm sure the integrated thinkers can suggest more....
I'm not normally impressed by car design, but the photovoltaic pavilion/ charging station Volvo have done to show off their deisel electric hybrid is just gorgeous.
http://www.autoblog.com/2013/07/16/volvo-pure-tension-concept-folds-sol…
Very interesting story and we need to look for a better future in renewable energy is the way to go this give us all some hope for a better future for our kids so let’s hope all these great minds find a way to improve the way we all live today.
Keep up the great work good story!
I had read a news report about a young guy who was building smart buildings with thermal energy (geothermal energy) where all the head of the building was channelled in to the group and the cooling from the deep earth was used to cool the building and the hear was also use to heat the water and other things in the building without using the grid very cool idea by Palestinian entrepreneur Khaled Al Sabawi has put Palestine of global geothermal map.
See: http://www.ecomena.org/renewables-palestine/ good read guys !!
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