Archive for January, 2009

Solar hot water systems require boosting. When the sun is shining, water is heated at no cost. Just think of those black-plastic camp showers or even a garden hose left on the ground on a summer’s day and you will quickly realise the power of the sun. However, during extended cloudy periods alternative sources of energy are required to heat water to appropriate temperatures.

There are two common options to heat and maintain your hot water temperatures during cloudy periods — electricity or gas. No matter what source is used, solar hot water still offers significant savings –  money and greenhouse-gas emissions.

Greenhouse Gas Comparison

A comparison chart is shown below which displays the reduction in carbon dioxide emissions compared to standard electric hot water systems. Surprisingly, in sunny states such as Queensland, according to the State’s EPA, up to 80 per cent of houses still purely use electricity.

Source: ENERGEX Institute

Note: Location is important when determining actual greenhouse-gas savings so visit the Your Home website for more details.

The chart also shows the difference between gas and electric boosting.

Gas boosting, more than halves the emissions generated by electrical boosting. This is mainly due to the efficiency of burning gas to produce heat compared to the low efficiencies of the generation and distribution of power via an electricity grid. Remember, the majority of the electricity grid is powered by burning coal, even if you are signed up to Greenpower. If your house is run by a stand-alone solar power system then gas boosting is essential.

Upfront Costs

Gas boosted systems, on average, cost $1000 more than the equivalent electrically boosted system.

Installation Costs

If you are replacing an existing electrical hot water system then most of the necessary wiring, minus the booster switch cabling, already exists. However, if booster elements are located on roof-mounted tanks then new cabling is required.

If you don’t already have gas installed, either as bottled LPG or natural reticulated gas for cooking, then gas-boosted systems may require higher installation costs, but this is highly dependant on individual circumstances.

Running Costs

The key to reduced running costs with either electricity or gas is correct temperature settings and appropriate boosting. Of course on sunny days running costs do not exist. However, extended periods of cloudy weather, or high water usage, means boosting will be required.

With gas boosted systems, often the gas burners are located inline after the tank, which allows the tank to store the maximum amount of solar-heated water without being affected by the boosting.

The recommended temperature of all hot water systems is 60 degrees Celsius. Lower temperatures will use less energy but the downside is, in storage tanks they also provide a great environment for bacteria.

The image below shows 7-year running costs for an average Victorian household. Once again these figures will vary depending on your location, the number of people in your house, and energy costs. It shows that gas-boosted solar hot water has the lowest running costs — almost directly related to the reduced greenhouse-gas emissions.

Source: http://www.yourhome.gov.au/buyersguide/bg6.html

And the winner is?

It really is dependant on your motivation. If costs are your primary concern then electrical boosted systems may be the answer, especially when you factor in the time to recoup the upfront and installation costs of gas systems.

If greenhouse gas reduction and lower running costs are the major issues, or you live on a stand-alone solar-powered electrical system, gas boosting would be worth investigating.

If it’s all too confusing then why not look at Ingenero (formerly SolarPay)’s obligation-free quote.

Planning to install a solar hot water system, or would you like to further reduce your power bills and install grid-connect photovoltaic panels on your roof? Perhaps you’re in the market to buy a greener, less fuel-hungry car?

Although solar hot water rebates and solar power rebates exist, the upfront costs are often seen as one of the biggest drawbacks. Rebates can take several months to arrive, and often you will need to pay the entire cost of the project upfront.

Fortunately there are a number of loans available targeted at sustainable, environmentally-friendly purchases. These loans are perfectly suited to the time-lag of government rebates.

What qualifies as an environmentally-friendly purchase?

Although variations occur between financial institutions, the list below shows the range of products that often qualify.

• Solar hot water
• Solar power and other alternative energy sources
• Vehicles with a 5 star environmental rating
• Grey water treatment systems
• Composting toilets
• Water tanks
• Energy efficient appliances
• Double glazing on windows
• Insulation

Green loans

Three financial institutions are listed below which display an example of the green and ethically-based loans on offer. They provide a good starting point for comparison. As with any loan, shop around and always seek professional advice. The interest rates listed below may change, so keep an eye on their websites.

The MECU goGreen home improvement loan — for a range of energy and water-saving devices with a minimum amount of $3000.

The Maleny and District Community Credit Union Green Appliance Loan — $2000 – $15000 with a variable interest of 7.45% p.a. for new loan applications. Comparison interest rate 8.00% p.a. Comparison rate is based on $15,000 over 5 years.

Bendigo Bank’s Generation Green Personal Loan. Offers fixed interest rate loans over a maximum of five years.

Government Green Loans

In mid-2009 the Commonwealth Government will introduce the Green Loans Program. To qualify for assistance you will be required to have a household sustainability assessment, which is designed to determine the most efficient alterations that should be made to your home.

It sounds like good idea to have an objective view of your house, with trained people offering suggestions to make your home more efficient.  Although many home owners may already know what they want and simply require the financial assistance.

However, if you like the suggestions in the assessment report they will offer Green Loan subsidies “through partnering financial institutions” for loans up to $10,000.

The budget for this program ($300 million over five years), is estimated to extend to 200,000 homes across the country, encouraging “an estimated $2 billion in green inspired investment for households – directly benefiting the small business sector”. Based on these figures it would mean an average loan would be only $1500.

Further information on the Green Loans Program will be released in the coming months.

It will be interesting to see which institutions are partnered with this project.

A recent CSIRO report, Energy use in the provision and consumption of urban water in Australia and New Zealand has highlighted the high environmental and economic costs of electric hot water systems. It also showed that the key to Australia’s energy savings is reduced, and more efficient water use.

With electricity prices rising by 17 per cent over the last two years and set to rise a further 14 per cent, energy efficiency is rapidly becoming a smart economic decision.

CSIRO scientist and project leader Steven Kenway was recently reported as saying: “the provision of urban water services uses relatively little energy compared to heating water for residential and non-residential purposes. A 15 per cent reduction in residential hot water use could offset all energy used by water utilities in 2006/07”.

“Saving hot water represents a real win-win-win: it cuts energy and water use for consumers, reduces energy demand for utilities and helps households and utilities save money on energy and water bills.”

Electric storage systems still dominate

The CSIRO report shows households in Brisbane and Sydney predominantly heat their water using only electricity. In Brisbane, over 60 per cent of households use electric hot water systems, 20 per cent use gas and only about 5 per cent use the sun’s energy via solar hot water systems.

Although off-peak electricity tariffs offer reduced costs, the storage and subsequent heat loss, means off-peak water heating results in higher greenhouse-gas emissions (GHG) when compared to heating during peak hours, according to the report.

“On average, 20 per cent of the energy used is consumed by standing losses, explaining why for many of the systems, the actual energy consumed is more than the energy required to heat the water.” These loses occur simply because the heat is lost from the tank and pipes, causing the thermostat to cycle the power on and off even without hot water usage.

Added to this is the fact that in “Australia, electricity is a relatively ‘dirty’ energy source in terms of GHG emissions due to the reliance of brown/black coal to fuel power stations”.

Cleaner, cheaper options

Gas-boosted solar hot water stands out as the lowest contributor to greenhouse-gas emissions. Even in the low latitudes of Melbourne, electric-boosted solar hot water produces slightly under half the greenhouse-gas emissions compared to the purely electric storage systems, while the gas-boosted systems can reduce emissions by over 90 per cent. If you live under clearer skies with greater level’s of sunshine, the news gets better.

A 2004 report, Modeling of Solar Contribution and Energy Savings of Domestic Solar Hot Water Systems in Brisbane, shows how suited solar hot water is for the sunny state of Queensland.

Solar hot water suits Queensland climate

Solar hot water systems, “can significantly contribute to reductions in fossil fuel energy consumption and greenhouse gas emissions”. Significant cost savings can be achieved by “careful management of boosting time, the use of AAA rated water conservation technology and the acceptance of minimum water temperatures down to about 50 degrees Celsius.”

The phasing out of electric water heaters in Queensland next year will not come soon enough. And these reports clearly reinforce the need to urgently move towards more efficient and cleaner ways to heat our water. I wonder if government rebates should be increased to hasten the process?