Renew Magazine

Visit Murrnong photo gallery

ReNew’s Open House Day was a resounding hit with locals and out-of-towners, nearly 400 of whom visited the open houses in Castlemaine in Central Victoria. But it was Murrnong, with its singular combination of architect-designed houses, sustainable features and co-operative living, that was arguably the scene-stealer of the day.

Legend has it that the queues to get into Murrnong were so long that punters had brought picnic baskets. Carolyn Neilson, who lives at Lot 2 at Murrnong, laughs at this. “It was great to have so much interest. It really validated what we’re doing. And it was wonderful for the kids to see that much enthusiasm about their home.”
Bought in 2003, Murrnong—which means yam daisy in an indigenous language—is a modest housing development of four individual blocks on 10 acres of partly-cleared bushland within walking distance of Castlemaine town centre. It operates under a registered body corporate plan which provides a framework for the community to evolve, and offers useful lessons to those interested in striking out in a similar direction.

Read the full article in ReNew 113

This is the device that converts the extra-low voltage DC electricity from the battery bank into 240 volt AC mains power to run standard appliances. It is important to have a good inverter—if your home relies solely on 240 volt power from the inverter and the inverter fails, you will have no power, even though it is still being generated and stored.

Inverters are divided into two main types depending on the type of power they provide—modified squarewave and sinewave. Modified squarewave (sometimes referred to as modified sinewave to make them sound better!) are the cheaper of the two, but some appliances (such as VCRs, TVs and computers) may not run as efficiently using this type of power, and some may not run at all.

On the other hand, sinewave inverters provide the same type of power that comes from the mains grid. Indeed, the power from a good quality sinewave inverter will usually exceed the grid in terms of quality and voltage stability. For this guide we will only be looking at sinewave inverters, as modified squarewave inverters are becoming less popular in fixed renewable energy systems as the difference in price between the two types steadily reduces.

REC stands for Renewable Energy Certificate, with these certificates being the trading currency for renewable energy in the renewable energy market. The value of one REC is equal to one megawatt-hour of renewable electricity generation (or in the case of some energy efficiency technologies such as solar hot water or heat pumps, one megawatt-hour of avoided electricity consumption).

Renewable electricity generators such as large wind farms, hydro-electric power stations or small-scale solar photovoltaic (PV) installations are able to create these RECs and sell them to the renewable energy market, thereby receiving a financial return.

The majority of RECs are purchased by electricity retailers, in line with their mandatory requirements set by the Federal Government under the Renewable Energy Target (RET). This cost to the electricity retailer is passed on to all electricity consumers (apart from a few large industrial users) in the form of a slightly higher charge per kilowatt-hour on your electricity bill. The Federal Government has recently expanded the RET so that 20% of Australia’s electricity supply (equivalent to 45,000 gigawatt-hours) comes from renewable energy sources by 2020.

What’s a REC worth?
Whether you’re a householder or a large-scale renewable energy developer, one of the key aspects of the market for any renewable energy investor is the variable price of RECs. The renewable energy market is a fixed market, with demand being mandated by the Federal Government each year. However, supply is not fixed, with any accredited renewable electricity generators being able to create RECs in any given year.

RECs are also traded through long-term contracts set up outside the electricity market. For example, a large wind farm operator might establish a contract with an electricity retailer to provide a fixed number of RECs for a fixed price over, say, five or ten years, in order to give both parties certainty regarding the supply and cost of RECs for business planning.

Recent RECs oversupply
Depending on the level of REC supply in the market, the price of RECs changes, similar to the price of shares. As an example, in April 2009 the price of one REC had reached a high of $54. By October 2009, with a significant oversupply in the renewable energy market, the price had dropped to $28. Historically, the renewable energy market has always operated with some level of oversupply, with more RECs being created than are required to be purchased each year. However, this oversupply has increased significantly in recent times, with the Federal Government giving more incentives to purchase solar hot water systems and heat pumps as part of the stimulus package, and under the Solar Credits Scheme (more detail on Solar Credits later in the article).

Greens senator Christine Milne has proposed that RECs generated by solar hot water systems and heat pumps be added on top of the Renewable Energy Target, so they are additional to the target and thereby don’t continue to decrease the value of RECs. It’s a complex problem: the drop in RECs value prompted by household energy efficiency incentives means that large-scale wind farm and solar investments are on hold until RECs gain value and can help fund big projects.

GreenPower and RECs
RECs can also be traded through the GreenPower mechanism. GreenPower is a voluntary renewable energy product that can be purchased by residential and business consumers to ensure that their electricity is tied to generation from renewable sources.

When a householder or a business purchases GreenPower through their electricity retailer, the retailer in turn purchases additional RECs from the renewable energy market. These RECs are purchased ‘in addition’ to the retailers mandatory requirements under the RET, meaning that the consumer has achieved investment and an environmental benefit on top of that mandated by the Federal Government’s target.
Solar credits and RECs.

One of the recent additions to the RET market is the Solar Credits Scheme. This new scheme came into effect in June last year, replacing the former Solar Homes and Communities Plan, which offered households a rebate of up to $8000 for the installation of a solar system.

The Solar Credits Scheme works by offering investors in small-scale renewable generation systems the ability to create and trade five times the number of RECs, thereby providing an increased financial incentive. This REC multiplier is available to solar PV systems up to 1.5kW in size, small wind turbines up to 10kW in size and micro-hydro systems up to 6.4kW in size. From mid 2012 the government plans to reduce this multiplier by a factor of one each year, until it expires in mid 2015, in anticipation of cost reductions in the small-scale renewable industry over that period.

One of the problems for consumers looking to invest in small-scale renewable energy systems under this new scheme is that it actually reduces the amount of new renewable electricity generation deployed in the market. If a householder can create five times the amount of RECs than normal (and bear in mind that small-scale generation units can create and trade RECs equal to 15 years worth of generation upfront), then for every five RECs created, four do not represent actual renewable electricity generation (i.e. four megawatt-hours).

These four RECs, once traded, will still be purchased by electricity retailers out of the market in line with their mandatory annual targets. In this way, investors in small-scale renewable energy systems are contributing to a reduction of the annual renewable electricity generation targets actually achieved. From the perspective of an individual household, one system may not make that much of a difference. However, given that over 70,000 micro-generation systems were purchased in 2009, the Solar Credits Scheme has the potential to substantially distort the achievement of the RET!

The way forward
Previously, many renewable energy system owners held on to their RECs to ensure that the renewable electricity generated from their system was additional to the mandatory government targets, as described in Don’t wreck those RECs in ReNew 105. Unfortunately, under the new Solar Credits Scheme, holding on to your RECs means that you miss out on any upfront financial assistance and pay the full retail cost of any solar, wind or micro-hydro electricity generation system. The Alternative Technology Association, along with a host of other environment, community and industry organisations, is currently lobbying the Federal Government to alter the Solar Credits Scheme to ensure the annual renewable energy targets are adjusted (i.e. increased) to account for the quantity of ‘fake’ RECs traded in the market.

In the long-term a much better mechanism to drive the uptake of small (and large) scale renewable generation is a strong gross feed-in tariff, whereby the investor knows exactly the price they will be paid for all the electricity they export and over what time frame, and the electricity networks know exactly how much additional distributed generation capacity is available. To date though we have seen only two effective feed-in tariff policies implemented for small-scale systems in Australia (in the ACT and NSW) and none for large-scale technologies.
With the current oversupply problems in the existing REC market and its inability to drive investment in the kind of large-scale renewable energy projects we need to deal with the climate crisis, the imperative for a strong, nationally consistent feed-in tariff to drive both small and large-scale technologies, complemented by a significant increase in energy efficiency investment, becomes more and more critical.

Hepburn Wind began five years ago in the towns of Daylesford and Hepburn Springs north-west of Melbourne. With help from developer Future Energy, the Hepburn Renewable Energy Association presented a permit application to Hepburn Shire in early 2007. Members later offered huge support to the project when its development was contested within the shire. The case received a reported 18 complaints and 320 letters of support.

These days the wind monitoring is all done and dusted. Having gathered three years of data from Leonards Hill, the mast was taken down in January. The cooperative is close to finalising the four major contracts: wind farm construction, grid connection, bank financing and the power purchase agreement. And they’re currently working on a plan with an energy retailer to allow the community and other groups to purchase branded power from the project.

Turbine selection

When it was time to choose a turbine, the technical people behind Hepburn Wind received unsolicited emails from start-up turbine manufacturers wanting to try out their product on a small demonstration installation. Following the global financial crisis in late 2008, it was even suggested that the project could go ahead using second-hand turbines. The technical team knew, however, that as they were building the first community wind project in Australia, the stakes were high and success was critical. It was decided that they could only go with highly regarded, internationally proven brands.

The Hepburn Wind project had a few extra criteria when searching for the right turbine, driven by the local community. Firstly, the turbines had to be very quiet, as the nearest houses are only just over 500 metres from the proposed turbine locations. Secondly, the turbines had a height limitation of 110 metres. If they were any taller the Civil Aviation Safety Authority can require blinking lights to be on at night, which the community didn’t want.

Pinning down a turbine manufacturer was challenging for Hepburn Wind due to the somewhat petite size of the order. Manufacturers more accustomed to receiving orders for 50 to 100 turbines at a time could conceivably push this smaller order to the bottom of their priority lists.

Fortunately, a German company called REpower Systems AG, came through with the goods. REpower already has a significant stake in Australian wind farms, as they are supplying turbines to the large Portland Wind Energy Project in south-west Victoria and six REpower turbines have been spinning since 2006 at Wonthaggi in eastern Victoria. Their machines are well respected internationally and known to be one of the quietest.

The MM82 proved to be the ideal machine for the site. It has a blade diameter of 82 metres and when operating at rated wind speed will generate 2050kW. This means that the two turbines will have a rated capacity of 4.1MW and over time will generate enough power for the twin towns of Daylesford and Hepburn Springs. Having received the order, REpower is currently busy organising contractors to do the civil and electrical works at the site. The final contracts are due to be signed as this article goes to print.

Grid connection

Grid connection for the wind farm has been a major technical hurdle. Powercor, the grid operator in the region, has never connected a wind farm of this size to the distribution network before and so a range of studies has been undertaken in order to ensure that the connection is smooth and doesn’t degrade the quality of the power in the area. Since there will be powerline upgrades in the area at the project’s expense, the Daylesford/Hepburn region is likely to have more reliable power after the wind farm is installed.

Due to the fact that Hepburn Wind is a community project, $15,000 per turbine per year will be put into the Daylesford/Hepburn area so that even the locals who are not investors will benefit from the proceeds of the energy sales. When construction is complete, it will be the closest wind farm to Melbourne, hopefully prompting a steady stream of visitors to the area.

In Europe, community-owned wind projects are commonplace. In Denmark, 5500 turbines are owned by over 200,000 community investors. And now that the first Australian one is close to being built, communities all over the country are asking Hepburn Wind how they did it. Having to take so many steps for the first time and the associated learning curve has meant that work has at times been hard and progress slow. But Hepburn Wind hopes that all the lessons learned will translate into a blueprint for others.

Renewable energy is just as important with the house that my wife and I are currently building in Port Germein. However, the renewable energy features have been installed from the very beginning, including the solar hydronic underfloor heating. Here’s how I did it myself.

To start off, I searched the internet for evacuated tube solar collectors. I found some in America which were reasonably priced; interestingly they were used for space heating as well as for hot water. I investigated transportation costs to reflect the true cost of buying from overseas.

In the end I decided to buy them locally from Sunplus CPC Solar in Victoria. I purchased a retrofit (conversion) kit containing four 12-tube collectors. With this kit came three pumps, two temperature pump controllers and some plumbing hardware. This was the easy part, now I had to decide on storage tanks.

Again I searched the internet for suitable hot water tanks. A local hardware store had some 315 litre tanks in stock. I took the model number, rang the factory in Sydney and asked whether it had internal heat exchanger coils. The answer was ‘yes, all our tanks have internal coils,’ so I bought this $1,000 tank, only to find out later that there were no internal coils in this tank. So much for correct information from the manufacturers!