Archive for September, 2008

A solar hot water split system only has the panels on the roof. The tank is on the ground in the same position that the old tank was in. That is the main difference of solar hot water heating systems.

Hot water rises up because it has less density than cold water. That means that a pump is necessary to pump the cold water up into the panels on the roof at the same time drawing the hot water down into the tank.

The pump is located on the tank. It is managed by a computer that measures the temperature in the panels and in the tank. Whenever there is a 6 degree Celsius difference (i.e. the water in the panels is 6 degrees warmer than the water in the tank) the pump starts working.

Two reasons for that:

1. You do not want to circulate the water at night or under clouds when there is no sun to heat the water in the panels
2. You want to use the heat as soon as the sun is hot enough, so even a 6 degree difference can make it difference.

But the water in the panels can get a lot hotter. That’s why the pump also stops working when the water in the tank has reached 75 degrees Celsius. That is much hotter than any electric hot water heater (they heat to around 60 degrees).

Hot water is highly corrosive. Basically there are two ways to combat the corrosion of tanks:

Vitreous Enamel

Vitreous enamel is a glass coating that is chemically bonded to steel at high temperatures around 850 degrees Celsius. It is actually glass powder that is used.

The enamel coating does not rust and thus prevents the water from reaching the steel.

In addition these tanks have a sacrificial anode for additional corrosion protection. It needs to get checked every 5 years and usually replaced after 10. In areas with aggressive or hard water, this might be necessary more often.

Stainless Steel

Marine grade stainless steel includes higher levels of chromium. They create a passive film of chromium oxide which prevents further corrosion.

Tanks made of it do not need any maintenance, but they are $600 to $1,000 more expensive than the vitreous enamel systems. It is possible to recycle the stainless steel, whereas the vitreous enamel tanks are just dumped.

For anyone living close to the Ocean, it might be a worthwhile investment, but for most situations the vitreous enamel work perfectly and give a better return on your investment.

How to Decide

When I started researching, all the stainless steel tank suppliers knocked the vitreous enamel tanks and the ones selling vitreous enamel showed me proof of how stainless steel can corrode as well. In reality both systems have been around for over 50 years and proved their longevity.

If you plan to stay in your home for 20+ years or you are close to the Ocean, the extra investment in a stainless steel tank might be worth it. If you are strapped for cash and want to start savings on your electricity bill, a vitreous enamel tank is a good and durable choice.

We recommend vitreous enamel as a standard, but offer to upgrade to a stainless steel tank.

Tank Casing

One last word on the tank casing. Most tanks come with a colorbond casing. It is a coated zincalume steel base, which is used extensively in roofs, walls, fences, garage doors, etc.

Last month (August 2008) the Deputy Premier Paul Lucas released a discussion paper on “Improving sustainable housing in Queensland“.

It consists of a 50 page brochure that explains a range of sustainability features that can be implemented in new homes or retrofitted in old homes.

Water and Energy are the two main components. Safety, security and access also rate a mention. It is a great starting point as it looks not only at the reduced environemental impacts of the actions, but also the financial impact to the individual.

In addition, there are a range of new rules coming into play in the coming years:

Phase out of electric hot water systems in 2010

From 2010 electric hot water systems that break down have to be replaced by solar hot water or gas systems.

Great step forward. Unfortunately it is watered down by a first stage that allows areas that do not have access to reticulated gas to continue buying electric hot water systems.

Sustainability Declaration at point-of-sale and point-of-lease

Whenever a house is sold or rented out, all sustainability features have to be disclosed. On the left you can see a sample of the forms to be used for that.

As this increases the visibility and awareness of sustainable features it is likely that valuations will take them into account. So capital returns migth even increase for sustainable housing.

Note: Greenhouse-efficient hot water (solar, heat pump, gas) is the first on the list.

All new houses need to be built to a 5-star rating

This could start to come into force as soon as January 2009. During the release there was a bit of discussion on how to rate homes without increasing the administration costs for that. Orientation using natural airflows and shading for heating and cooling impacts the strongest on this rating. But it might go into as much details as which building materials are being used.

Lack of Interest

The most surprising thing was that only 20 or 30 people actually came to the release of this paper. There are hundreds of developers and builders on the Sunshine Coast alone that might be impacted by these changes. Are they not interested, because it comes from government? Or because they do not understand sustainability?

Lesley Gillett has lived in Buderim for 11 years. At a community forum in March this year, “Changing the Dream” she has realised that the only way to make a change is to take action. Ever since then she has not stopped networking, talking to neighbours, to the press and reaching out to the business community to create awareness and action.

One of her big goals is to bring the Buderim community together to take action. With the help of the Sunshine Coast Regional Council, Lesley is organising a Resilient Buderim Gathering at 7pm on Wednesday 19 November. It will be held at the BWMCA Hall.

If you are interested in attending, you can call her on 07 5445 2870.

Join the Buderim Solar Bulk Buying Initiative

One of the projects is a bulk buying group for solar PV and solar hot water. Bulk Buying is a community initiative that  works because it shifts negotiating power in favour of the individuals. It also cuts out marketing costs that can be passed on as savings.

Here is how it works:

1. You go through the instant online quoting process.
2. The online calculator finds the best system for your situation, shows all rebates and gives an expected price.
3. Once 10 people have registered their interest, we’ll give you a call and confirm the final price.
4. You can then decide to go ahead and we install within 3 weeks.

Other Bulk Buying Initiatives

Sustainable Maleny is also in the process of organising a solar bulk buying group. About a year ago they have successfully organised a solar hot water bulk purchase and now they are working on a solar photovoltaic project.

We are also in the process of putting one together for Brisbane and I’ll have the details in a few days.

If you know of any other bulk buying initatives, please write a comment below, so we can publish it.

The Brisbane City Council has officially introduced a rebate for the installation of solar hot water in Brisbane.

The first 1,500 eligible residents receive an additional $400 off the standard solar hot water costs – on top of the $1,600 federal rebate and the renewable energy certificates (this payment varies and is currently between $1,500 and $2,000).

As a participating supplier, Ingenero (formerly SolarPay).com.au offers the rebate as a Point of Sale discount. You will see it when you go through the quoting process.

As with all other rebates, we look after the forms and handle the council contact. So all you have to do is to make a decision to go ahead.

With our stall at the Riverfestival yesterday, we have already spoken to many interested people (along with 4 other suppliers).

Brisbane Has Seen the Light

It is great that the Brisbane City Council has realised that solar hot water is the single biggest consumer of electricity in every household. Lord Mayor Campbell Newman highlighted that for most people it will only be a 4-5 year payback and then they save money “year after year”.

In his speech, he also points out that solar hot water will make a significant difference to the hip pockets of householders across Brisbane.

I hope that the council gets absolutely overwhelmed with the response and has to figure out how to make the rebate available to many more householders than they are planning for now. And that other councils who want to reach sustainable targets follow suit.

Good on Brisbane for taking that initiative. And thanks a lot to pigswillfly.com.au for alerting me to it.