Archive for June, 2008

The main difference in solar hot water heating systems is where the tank is located.

On-roof Solar Hot Water Heating Systems

With on-roof or roof mounted systems, the tank is directly above the collector panels.

Hot water is lighter than cold water, so it naturally flows up into the tank (or rather gets pushed up by the colder water sinking down).

Water flow happens through the mains pressure. As hot water is taken out (from the top), new cold water flows in and gets heated up in the panels.

Using these natural physical laws makes it reliable and cheap to run.

The disadvantages: You might not like the look of the tank on the roof.

There are also some situations were the hot water would need to travel too long before reaching your shower. In such cases, a lot of water is  wasted and we recommend the split systems.

Split Solar Hot Water Heating Systems

A split system only has the collector panels on the roof. The tank is located where your current tank is.

A small electrical pump is necessary to pump the hot water down from the panels into the tank. However, the energy for the pump is offset in reduced heat losses, as the tank is more protected.

If the ideal location of the collector panels is far away from the location of the old hot water tank, a split system will result in better water usage. The reason is that the hot water is stored closer to where it is used. That means you do not have to wait for the hot water to reach your shower.

An added advantage is the in-built frost support. If the temperature falls below 5 degrees the pump automatically starts circulating the water. That brings warmer water back up to the panels so that the chances of it freezing are reduced.

The disadvantages, slightly more expensive to buy and install.

How to Decide?

When you go through the quoting process for your solar hot water heating systems, you get a choice between the two kinds of systems (where your situation makes that possible). To make the right decision, consider:

• The distance of the collector panels to the old tank (the further away, the more it makes sense to get a split system, e.g. two-story house)
• Your aesthetic preferences
• Your finances (how quickly you want to be paid through your investment)
• Future value of house. Whoever purchases the house might prefer a split system.

Some of the answers you give might rule out an on-roof system anyway, then you just need to decide on tank size.

One of the issues that came up in the interviews at World Environment Day was the question of the reliability of solar water heating.

Some people have experienced problems with earlier systems that did not have enough capacity to handle a few days of grey skies.

There are three components to that issue

1) Tank Size

All tanks have great insulation, so that the heat-loss over a few days is minimised. The more important factor is how much hot water is used. According to the Sustainable Energy Development Office of WA an average person uses 50 Litre of hot water per day.

The water in the tank heats up to 90 degrees in summer, but gets mixed with cold water when it comes out (to 50 degrees, so that no one gets burnt). That means a 300 Litre tank has a capacity of close to 550 Litre of 50 degree water. So for a family of four, it can last close to 3 days without any sunshine.

So the bigger the tank, the more hot water you bank.

2) Solar Water Heating Collectors

Efficiency of collectors depends on a lot of factors. We check them all on this website and then again before installation to make sure you get the best efficiency out of your system.

We use the highly efficient technology in all our split solar hot water systems that can face anywhere from North-East to North-West to work well. You need to get an absolute minimum of 4 hours of sunlight on the panels to successfully heat your tank.

3) The Booster

The last element in solar water heating is the booster. It has a thermostat that is set to 60 degrees. So whenever the water temperature falls below 60 degrees, it automatically heats it up.

Conclusion

Is solar hot water heating reliable? Yes absolutely. The technology is well matured since the 1950’s. It is highly efficient (up to 80% of the sun’s energy is turned into hot water) and it has a reliable backup with the booster.

World Environment Day was a great success. The Ingenero (formerly SolarPay) team spoke to more than 2,000 people about solar hot water. Many were astounded at the general environmental benefits as well as the personal financial benefits.

As part of the day, we conducted a survey to see what stops people from purchasing solar hot water. The positive result: 70% had considered solar hot water. However, only one third had actually taken action.

Cost was by far the biggest reason cited as to why they had not gone ahead. 55% thought it was too expensive. However, they did not realise that the current rebates are at an all-time high. And when they heard about the partnership with NAB for finance with no upfront payment, many pledged to check out this website for their options.

Visitors were intrigued with the possibility of solar hot water without any upfront costs and then using the electricity savings to repay it.

Now I am hoping that the buzz we created on the day, flows out into our community. On the Sunshine Coast there are 52,000 freestanding houses that are owner occupied. If every one of those took action, we could avoid 3.1 Million tonnes of CO2 (see solar hot water facts).

And that without spending a single additional cent, in fact each individual who gets solar hot water will be better off financially (up to $12,000) and have the full convenience of hot water.

The Queensland government has started a new program called ClimateSmart Home Service. For $50, a consultant comes into your home, does an energy audit, changes over lights to the compact fluorescent light globes (up to 15), installs a water efficient shower head and provides an energy meter that shows the electricity usage.

The program does not start until January 2009, but you can register your interest here.

According to ClimateSmart.qld.gov.au 75,000 Queenslanders have already signed up for the service. That is really amazing, but confirms that Queensland is quite advanced in energy efficiency.

During our research, we also noticed that Queensland leads the way in how many solar hot water systems are installed. In the last 8 years, it always had the highest uptake from all the Australian states. That trend continued even after the Queensland state rebate ended in 2005.

That shows that government incentives have a positive effect that flows on well into the future of the incentive.

Renewable Energy Certificates (REC) have been set up by the Australian government as a form of currency. One REC can be created for every kWh of renewable energy that is produced.

Energy retailers on the other hand need to surrender enough REC’s each year to contribute their share to the Mandatory Renewable Energy Target.

Even though a solar hot water systems does not produce electricity, it produces energy in the form of hot water. Rather than measuring the actual output, a deemed number of REC’s is associated to each model of solar hot water unit. This varies depending on where you are located in Australia (your quote includes exact details).

Your obligation

It is up to you to create the REC’s. However, we prepare everything for you and actually reduce the price by what you get for the REC’s. That way you do not have to pay it first and then get it back. Instead you only have to check and sign the pre-filled form.

Please note that this is different to the Federal Solar Hot Water Rebate, which we cannot claim on your behalf.

Your choice

You may choose to voluntarily surrender your REC’s. That means that you indirectly help to create more renewable energy. If you do that, you cannot sell the REC’s and need to pay an additional $1,400 to $1,800.