Solar energy is the single most abundant form of renewable energy in the world. It is the energy that comes from the sun in the form of sunlight. This energy can reach the earth's surface with a maximum intensity of more than 1000W/m².
Solar heating is the process of taking the solar energy and converting it into usable energy for heating water.
There are two types of solar water heating systems available in New Zealand:
There are two ways of getting the heat from a collector panel to the storage container:
There are two types of collector both of which have a number of variations in specific design.
A Solar water heating system can be supplied as a packaged system or custom built.
Where a solar water heating system is supplied as a packaged system it will be supplied with all components (tank, collector, pump, controllers) which have been designed for complementary and optimal energy performance. Systems supplied and installed as complementary packaged systems can be tested for energy performance as packaged systems with nominated sized and type of containers, and any claimed performance relate to the system as a whole.
A customised system may be constructed for a special application or be where solar components from a packaged system are connected to an existing hot water cylinder. Such systems should only be put together by Approved Installers from components of packaged systems and connected to other existing components such as a hot water storage cylinder. Where systems are custom built using components, suppliers must be able to provide evidence that the individual components meet the appropriate standard tests, and that the customised system as a whole meets any claimed performance levels by demonstrated similarity of performance to a representative product that meets the requirements of the standard.
For
more information on solar water heating click here.
As a member of the Association manufacturers and importers of overseas manufactured equipment are required to periodically demonstrate that the equipment meets the manufacturing and operating standards set by the Association from time to time and that the equipment supplied will be consistently manufactured and supplied to meet the required equipment standards. For more information on the manufacturing standards and where to get system testing click here.
The Association has developed a "Solar Water Heating and Manufacturing and Installation Code of Practice for New Zealand". The currently approved code is available here. Associated with the Code is a "Manual for Structural Assessment for Installation of Solar Water Heating in Domestic Dwellings" available here.
SIA administers the Code on behalf of the industry. Any comments or suggestions for improving the Code are welcomed and should be forwarded to the SIA Executive Officer.
Installation of solar water heating systems is regulated by the need for Building Consents from local Councils. To obtain a Building Consent the system installer needs to demonstrate to the Council Building Inspectors that the system installation will meet the NZ Building Code. The Code establishes the standards for installation. In particular for safe loading on roofs and safe supply of potable water.
The SIA Code of Practice sets out for Councils, the solar industry, and the public the compliance standards and good installation practices that all installations should achieve. These are set out in Clause G12 of the Code. Compliance can be achieved by installations being done to meet the Acceptable Solution G12/ASI. A specific Acceptable Solution for SWH (G12/A52) is in preparation and a draft is available here.
The government is currently undertaking a review of the Building Code. In that review the SIA position is that;
The Solar Industries Association (SIA) will assist with the review to ensure that solar water heating;
New Zealand currently provides more than 40GWh of equivalent electricity consumption per year through the use of solar water heating. It is widely thought that by 2010 this figure could be upwards of 600GWh per year. The total amount of solar energy that the New Zealand land mass collects is approximately 400 million GWh per year which gives an indication of the potential for solar energy use.
Currently the two major regions at the forefront of solar technology are Australia and Western Europe. The abundance of sunlight in New Zealand places us on an even par with the levels found in Melbourne and above that of the levels found in Europe. This shows that the future of solar heating in this country is very attractive and with greater knowledge of the technology, we can only assume steady growth.
For more information on the potential of solar heating click here.
The various advantages of solar heating include:
Purchase and installation costs of a commercial solar hot water system in a domestic residence are in the range of $4000 to $7000 depending on:
Only systems that have been independently vetted as complying with the New Zealand manufacturing and safety standards should be purchased. Other systems may or may not be safe and well manufactured but unless independently vetted their suitability is untested.
In general complying systems will operate very similarly at different locations throughout New Zealand. The biggest difference will arise from the experience and capabilities of the installers. Using an Accredited Installer will assist ensure that the energy performance of the installed system is optimal.
There are however difference in system design that purchasers should address when choosing a system:
The means of control of supplementary heating
Design and configuration of hot water storage tank
Means of freeze protection
There are a number of suppliers of different solar hot water systems. Each system will have a number of different manufacturing and performance characteristics. To choose the system that meets your situation you may find this check list useful:
Does the supplier:
hold Accreditation for the Supply and Installation of SWH Systems from the Solar Industries Association? Only Accredited Suppliers have been independently vetted as complying with the solar Code of Practice, which assists to ensure that their products have been tested and their service is satisfactory.
have an Approved Installer in your area who has been trained by a product distributor or the Accredited Supplier and is experienced and familiar with their range of products. Can the Approved Installer show you documentation that shows that he/she is fully trained to install this distributor 's systems? More than 85% of solar performance issues are related to poor installation.
provide you with satisfactory answers to your questions?
provide you with a clear specification of what equipment they will provide, who will install it, the relationship with other trades people, access requirements, layout and installation aspects?
provide you with good clear documentation of what energy performance you can expect from their system for your house design, location, direction, and for each of the seasons? For energy performance information click here.
have a quality system for supply and installation that is demonstrable? (such as ISO9002)
have a history of supplying and installing sound efficient systems?
confirm that the system has been built and will be installed to the SIA Code of Practice?
undertaken to obtain the Building Consent required by your local Council. A Building Consent can be costly to obtain unless the Building Inspectors can be assured that the installer knows what they are doing and that it is actually done.
have documentation (such as owner's manual) showing on-going maintenance requirements?
have a design that will meet any frost, electricity supply interruptions, overheating safety events?
provide a written guarantee?
undertake to provide you with an owners manual after installation?
have a record of being a sound business that is likely to be around to fulfil their guarantee obligations?
provide references to other successful installations that you can follow up?
have a price that is right for you?
The SIA has a number of members who are focused on meeting the customers needs – hot water, and supply both SWH and HPWH systems. Suppliers often offer SWH and HPWH systems as they are seen as being complementary and the potential customer can be offered the best hot water supply solution appropriate to their situation. Customers generally don’t want to buy a particular technology, eg SWH or HPWH per se, they want the best hot water solution for their needs.
When building a new home you should always look to heating water by the best long term sustainable method. This will be by use of a solar water heater.
It is generally accepted that the primary technology for water heating should be from renewable energy sources such as solar. However there are a number of situations where solar heating is not appropriate and heat pump water heating (HPWH) technology is the next best option and should be installed. Clearly renewable energy must be promoted over greater use of electricity.
Situations where HPWH is more appropriate than SWH would be in areas where the location has a high degree of shading, there is no appropriate north facing roof area, or the quantities of hot water used are small.
Internationally technical standards for SWH and HPWH are often combined as many aspects of each technology are common. This also occurs in New Zealand where the standards AS/NZS 2712 and AS/NZS 4234 both cover SWH and HPWH.
For further information on HPWH click here.
In many areas of New Zealand there is an option for heating water by use of gas. Where that gas provides supplementary heating for a solar system this can be an ideal combination. Usually solar is the primary heating system with continuous gas heater boosting the temperature of the water if the solar has not heated it adequately.
Installing a wood pellet heater with a wet back or a wood pellet boiler as supplementary heating to a solar system so provides year round supply of hot water for renewable energy sources.
There are a wide number of typical situations where solar water heating is being installed. Examples are shown on the attached reference sheets.
Solar Water Heating Reference Installations 1.
All members of the Association are expected to meet the Association's Code of Conduct. For a copy of the Code of Conduct click here (pdf 26kb).
Harnessing the Power of the Sun: Future of Solar Energy, presentation to Clean Energy Summit, Auckland on 1st and 2nd December 2009 (download pdf 0.99MB)
Ensuring Quality Installation of Solar Water Heating Systems, presentation to Building Officers Institute of NZ Annual Conference, Auckland on 23rd April 2008 (download pdf 803KB)
Solar Water Heating and Plumbers (download pdf 281KB)
Useful Sites
American Solar Energy Industries Association
The American equivalent of SIA.ANZSES
The Australian and New Zealand Solar Energy Society.Consumer Solar Water Heating Buyers Guide
EnergyInfoNZ
This is a portal for access to energy based information including solar energy and other energy forms.Energy Library & Information Services (EnergyLibrary)
An independent provider of information with search capabilities for accessing publications from around the world.Energy Efficiency & Conservation Authority
New Zealand Crown entity to encourage, promote and support energy efficiency, energy conservation and the use of renewable sources of energy.IEA Solar Heating and Cooling Programme
The International Energy Agency solar heating and cooling Research Programme.Sustainability Victoria, Melbourne, Australia
The Australian Renewable Energy Industry AssociationWood Energy
View the Bioenergy Knowledge Centre for information and tools for utilising wood waste as a renewable energy source.
