PV solar from toy-size to utility-scale

Tandy 'Science Fair' Solar Power Lab, c. 1978
Tandy ‘Science Fair’ Solar Power Lab, c. 1978

We came across a time capsule when we were clearing out a spare room a few months ago: a ‘Solar Power Lab’ given by one family member to another nearly forty years ago and passed down through the family ever since.

Project list
Project list

Photovoltaic cells were cutting-edge technology back then. The cells in the  kit – four of them, each about 5 x 1 cm, in a line along the back of the circuit board – were novel enough to be the selling point of an otherwise unremarkable electronics construction kit, and may well have accounted for half the cost of the kit.

The introduction to the manual, like the box, was all about the ‘space age’ technology used to power satellites – which were big news themselves in those days.

The ingenious recipient could construct any of twenty-odd projects, from logic gates (these were the days when home computers with 64KB of memory were considered powerful) to LED demonstration gadgets (LEDs were new, too) to transistor radios.

Construction manual
Construction manual

Moore’s Law was relatively new back then, too. I wonder how many people had any idea what its impact would be over the ensuing forty years? The purely quantitative differences have been so large that they have led to qualitative differences (from “big data” to the ubiquity of mobile phones.)

And solar power has grown almost beyond belief, too, on a similar path of dramatically falling costs and steadily improving efficiency. This ThinkProgress article presents a good overview of the current state of play, with one chart which sums it up beautifully:

Solar’s exponentially declining costs and exponentially rising installations (the y-axis is a logarithmic scale)
Solar’s exponentially declining costs and exponentially rising installations (the y-axis is a logarithmic scale)

Progress hasn’t been as rapid in solar power as in computing (Varun Sivaram explains why here, if you’re interested) but has been enough to overtake older technologies and to transform our future.

Once again, quantitative improvements have led to qualitative changes. Solar power is no longer a novelty and no longer a last resort for difficult situations such as satellites, but a realistic, cost-effective solution for all sorts of applications. Garden lights? Solar, of course – it saves wiring them in. Bore pumps? Solar, of course – no need to cart diesel down to the pump every few days. New suburbs? Solar with grid backup – not even vice versa. Parking meters? Lanterns for remote PNG villages? Traffic hazard warning signs? Domestic hot water systems? Solar, solar, solar.

Having kittens

It is an embarrassingly long time since my last post but a large part of the reason is that I was busy doing other good things, so I don’t feel quite so bad about the gap as I would otherwise have done. My major project was setting up the website for Kittens for the Reef, a cute video which I think everyone should watch:

Kittens for the Reef was launched on May 31 by one of its stars, Dr Charlie Veron (Fluffy couldn’t make it) at Townsville’s Eco-fiesta, an annual event which brings together all sorts of greenies. I attended and enjoyed it, as I have in previous years.

There is usually a new gadget or idea which catches my attention more than the others, and this year it was a cleverly designed and engineered portable solar power system from SolairForce. As their brochure (pdf) says:

The Solairforce PPS is essentially a Solar charged battery system with a pure sine wave inverter which is portable and able to be used in a variety of applications. It is able to be charged via solar or a mains battery charger and has a deep cycle battery storage component. The Solairforce PPS has 12v DC, 240v AC and USB capabilities.

But that sells the engineering short. Everything except the panels sits snugly in a weatherproof, waterproof plastic chest that looks like a heavy-duty Esky, with air vents on each end and a row of weatherproof outlets on the front.

When it comes to applications, the brochure is much better:

The Solairforce PPS has a wide variety of applications which include but are not limited to:

  • Off Grid system able to be connected to domestic houses to save buying grid power
  • UPS system for computers and servers
  • Emergency power (including medical devices)
  • Remote area power supply?
  • Camping , RV’S, Caravans
  • Tradesmen and builders on job sites
  • Disaster relief?
  • Boating
  • Mining, underground or confined spaces
  • Power supply for transportable buildings

I have bolded the applications in which I think it is going to be particularly valuable and, of these, disaster relief is the stand-out. MSF, Red Cross, Oxfam, etc, please take note!  The developer doesn’t have a full web site devoted to the system but is on Facebook.

Going solar – two updates

I have been connected with two domestic solar power projects which I described here on Green Path at the time, and today I have news on both of them.

Hervey’s Range in winter

The first item concerns our solar bore pump on Hervey’s Range: we pulled down the disused power line over the weekend and took it to a scrap metal merchant. Pulling it down made the property tidier and safer and was a good excuse for mucking around in the bush for a few hours on a beautiful sunny day, while the $150 we got for it was a belated cash-back bonus on our purchase of the solar pump system. 

The system itself, six months down the track from its installation, has performed well. Cloudy weather has not troubled it as much as we thought it might, and neither has the shorter span of daylight in winter.

Back in town, the 1.5 KW system we put on our roof has just passed a good round number in its total output: 7 000 kWh, or 7 MWh. We installed the system in May 2011 so it has produced an average of 6.2 kWh per day for three years. By power-station standards that’s nothing, of course, but it’s a useful percentage of a household’s consumption: Ergon says (on the back of our power bill) that the average daily consumption for a household like ours is about 20 kWh per day, so our panels are producing nearly a third as much as we use.

Of course, we use some of our solar power during the day and export the rest of it and then use Ergon’s power all night, so our net benefit doesn’t quite reflect those numbers. I did the sums a year after the installation and came up with a figure of $700 p.a., with the expectation that that would increase as power prices increased.

The general tariff has just gone up from 29.4 to 30.8 c/kWh, which doesn’t look like a big change until you note that the same tariff was only 19.4 c/kWh when we installed the system three years ago.

In May 2011 the “service fee” or “daily supply charge” was only $23 per quarter, whereas by May this year it had risen to 55 cents per day ($49 per quarter) and it has just increased to 92 c/day (about $83 per quarter). That will make it a major part of our power bill.

The huge increase in the supply charge is obviously Ergon’s attempt to make up for people like ourselves who still want the security of mains power but don’t actually use much of it because we generate a lot of our own. That’s fair enough, maybe, but it simultaneously encourages us (and people like us) to go completely off-grid. I will return to this scenario in another post; meanwhile, Australian households could go off-grid by 2018 is a thought-provoking introduction to it.

Put Solar On It!

putsolaronitFor a while now I’ve been collecting snippets of news about innovative – or just plain smart  – uses for solar photovoltaic power (PV) with the intention of posting them to Green Path. When I read about an American day of action coming soon, #Put Solar On It!, I decided I should assemble my finds now rather than later.

#PutSolarOnIt brings together the strength of Organizing for Action, Mosaic, The Solar Foundation, Solar Energy Industries Association, SolarChat, Vote Solar, NRDC, Interfaith Power & Light, Sierra Club, Environment America, World Wildlife Fund, REVERB, The Climate Reality Project, Alliance for Climate Education, League of Conservation Voters  and The Solutions Project.

This June 21st, the longest day of the year, a coalition of groups will come together in a National Day of Action to show support for switching to clean energy, fighting climate change, and the power of bringing solar power to communities all across the country. …

All across America there are opportunities to #PutSolarOnIt – to turn our homes, our churches, our schools our lands and our neighborhood rooftops into solutions to climate change. June 21st is a National Day of Action for us all to find a way to #PutSolarOnIt by identifying, supporting, and rallying our social networks to support solar energy, or joining a local event to support a community based solar installation.

Their press release also notes that …

2014 has been a breakout year for solar. Solar equipment costs continue to come down and installations continue to grow. More solar energy generation has been installed in the U.S. in the last 18 months than in the 30 years prior, and solar energy is the leading source of new electric generation capacity so far this year.

– and this is in spite of a sustained Republican campaign to block any and all renewable energy initiatives.

Anyway, back to the good stuff, the ingenuity and innovations. As in previous collections here, I’ve linked images to sources where I can. After collecting items for a while I realised that a lot of them involve transport. That’s a Good Thing, to my mind, since transport has always looked liked being one of the hardest areas to decarbonise because it requires compact portable power, and I will start with them.


PV trees make shade sails and a recharging station for electric cars. Townsville airport has had a smaller, simpler instance of the same idea since 2011 – see it on YouTube here. Or there’s the no-frills (but still really useful) version here.
Of course, if you know you won’t be near a facility like any of these, you can take your own gorgeous solar umbrella with you and erect it as you leave your car.

Solar roads, which in practice may begin as driveways, bikeways and car-parks.

Solar cars (and don’t forget the World Solar Challenge).

There’s probably a partially solar powered car in your future, but I wouldn’t bet on a solar powered plane – however pretty this one is.

Good places to put lots of solar panels

solar-airport• Airports – whether closed down, as at left, or fully functional as here – are wide open spaces near urban areas, already kept clear of trees and tall buildings which might shade any panels.


• Canals (above) and dams – reducing evaporative water loss as well as making electricity.

• Football stadium – one good outcome of the World Cup building programme in Brazil.

The price of solar cells has dropped to a point where unsubsidised solar power is cheaper to install than coal-fired power and the reliability and longevity of solar power installations is beyond doubt. Solar power now seems unstoppable and stories like this one on Think Progress drive home that point. Its last line, “shifting economics has increased interest in Texas’ long-untapped solar power potential,” is code for, “coal is no longer a profitable investment,” something for which the environment should be profoundly thankful.