Appendix 1: Design Standard for Woodburners - Costs and Benefits
This appendix summarises the Environet Ltd report prepared for the Ministry in 2004 (in press).
A1.1 Current situation
There is currently no mandatory emission level for wood burners installed in most areas of New Zealand, although a large proportion of appliances are tested to NZS 4013 and comply with the 4.0 g/kg emission limit specified in that standard. The New Zealand Home Heating Association website provides a list of appliances currently tested to NZS 4013.
Estimates of future PM10 concentrations and health impacts if national environmental standards or additional controls are not introduced within New Zealand urban areas that currently exceed ambient air quality guidelines are outlined in the Ministry for the Environment's A National Environmental Standard for Solid Fuel Burners: Assessing the impacts (2003a). These are approximate estimates only and are based on existing information on home-heating methods and patterns, population projections, existing emission inventory data, Ministry of Transport estimates of variations in tailpipe emissions from motor vehicles, and assumptions relating to changes in industry.
In addition, the home-heating estimates are based on the following assumptions.
- All new wood burners installed within new homes meet the proposed standard option.
- Old existing wood burners are replaced with ones that meet the proposed emission limit approximately 15 years following installation.
- Wood burners operated in a real setting will not achieve the test emission rate.
- The current requirements of the regional councils represent the status quo.
- Some wood burners are not included in the standard and therefore can be installed, unless not allowed through a regional plan.
A summary of the estimates for all areas where PM10 concentrations have exceeded ambient air quality guidelines for PM10 (Ministry for the Environment, 2002a) is shown in Table A1.1. Subsequent estimates of the impact of introducing national environmental standards of 4.0 g/kg, 1.5 g/kg and 1.0 g/kg are also based on the latter assessment, with modifications to emission factors for new wood-burner installations.
Table A1.1: Estimated health impacts associated with PM10 concentrations in New Zealand - status quo
Table A1.1 shows a decrease in the number of breaches of the PM10 guideline (50 µg/m3, 24-hour average) across New Zealand in the absence of further controls. This occurs as a result of existing or proposed air plans (e.g. Christchurch and Nelson), as well as gradual reductions in domestic heating emissions of PM10 as older, more polluting solid-fuel burners and open fires are replaced with modern solid-fuel burners. Although the installation of new open fires is permitted in most areas of New Zealand, few households appear to be installing new open fires.
A1.2 Benefits
A1.2.1 Introduce a standard of 4 g/kg
The introduction of a national environmental standard for wood burners of 4 g/kg is likely to result in some improvements in PM10 concentrations across the whole of New Zealand. However, the reduction achieved is limited because many existing wood burners available in New Zealand currently meet these emission levels and because a number of high-exposure areas (Christchurch, Nelson, Auckland and Otago) have already implemented a mandatory emission limit of 4 g/kg or less.
The estimates of impact shown in Table A1.2 are based on an emission factor of 4.4 g/kg for the new installations of wood burners. This emission factor was selected after evaluating emission test results for burners complying with the 4.0 g/kg emission limit and emissions results for wood burners under simulated operating conditions, as detailed in section 4 of this report.
Table A1.2: Estimated benefits of introducing a standard for wood burners of 4.0 g/kg
View estimated benefits of introducing a standard for wood burners of 4.0 g/kg (large table)
A1.2.2 Introduce a standard of 1.5 g/kg
The introduction of a national environmental standard for wood burners of 1.5 g/kg is likely to result in significant reductions in PM10 concentrations and associated health impacts in New Zealand. Table A1.3 suggests a significant reduction (29%) in the maximum number of days 50 µg/m3 (24-hour average) is likely to be breached in urban areas of New Zealand, and a reduction in mortality of around 11% may occur by 2013 as a result of introducing a standard of 1.5 g/kg.
These estimates are based on an average emission factor of 3.0 g/kg for wood-burning appliances meeting a test criterion of 1.5 g/kg. This is based on simulations of real-life emissions and testing carried out by Applied Research Services for Environment Canterbury during 1999 and as a part of a study funded by the Sustainable Management Fund during 2003. Further details on the selection of the emission factor are discussed in section 3.
Table A1.3: Estimated benefits of introducing a standard for wood burners of 1.5 g/kg
View estimated benefits of introducing a standard for wood burners of 1.5 g/kg (large table)
A1.2.3 Introduce a standard of 1.0 g/kg
Based on the limited test data available, it is unlikely that the introduction of a standard for wood burners of 1.0 g/kg will result in additional reductions in PM10 concentrations above what might be achieved with a standard of 1.5 g/kg. Results of emission testing for sub 1.0 g/kg burners under simulated operating conditions are summarised in Ministry for the Environment 2003a. These do not support the assumption that a reduction in the test emission criterion below 1.5 g/kg will result in subsequent reductions in real-life PM10 emissions. Consequently, the emission factor of 3 g/kg, as per the 1.5 g/kg wood burners, has been used to estimate the impact of a standard of 1.0 g/kg. Table A1.4 indicates that the introduction of a standard for wood burners of 1.0 g/kg is unlikely to improve PM10 concentrations and subsequent health impacts relative to a standard of 1.5 g/kg.
Table A1.4: Estimated benefits of introducing a standard for wood burners of 1.0 g/kg
View estimated benefits of introducing a standard for wood burners of 1.0 g/kg (large table)
A1.3 Likely costs
The costs associated with implementing a national environmental standard for wood burners include:
- getting appliances tested and approved.
- administration and compliance monitoring costs.
- A reduced choice of burners for householders.
- manufacturers being unable to sell appliances not meeting the required emission limit.
A1.3.1 Administration costs
Administration costs include the cost of the approval process, maintaining a database or list of approved appliances, and education relating to the proposed standard.
The approval process involves examining the wood-burner test report, design specifications of both prototype and production model, and labelling. The current cost of approval by a regulatory authority is about $1,000 per application for Environment Canterbury-approved appliances, but it can be double this if there are significant discrepancies between the appliance design specifications for the prototype and the production model.
A list of approved burners could be established on the Ministry for the Environment website. The costs associated with developing the page within the website and updating it with burner approvals would initially be around 20 to 30 hours for establishing the web page and less than 30 minutes per burner.
Education costs include the preparation of an information sheet or pamphlet, printing costs, and time associated with contacting manufacturers and retailers and liaising with territorial authority staff. Most of these would be one-off costs that would occur when the standard was introduced. However, some ongoing maintenance of relationships would be required.
A1.3.2 Compliance monitoring / enforcement costs
Compliance monitoring costs include time and travel expenses associated with checking that wood burners available for installation comply with the design specifications of the approved wood burners.
Enforcement costs include time liaising with burner manufacturers in the case of non-compliance, and the costs of any subsequent enforcement action.
A1.3.3 Manufacturers' costs
Manufacturers currently pay around $8,000 per burner for emissions testing to NZS 4013. This testing is typically carried out at Applied Research Services in Nelson, although Coal Research Limited (CRL) is also likely to offer emission testing to this standard in the near future. As a number of regional councils already have mandatory emission limits for new installations of solid-fuel burners, most manufacturers already carry out emission testing on their appliances, so the introduction of a national environmental standard would not result in significant extra testing costs for most manufacturers.
At present, regional councils can recover the costs associated with the approval process from the manufacturers of solid-fuel burners. This typically results in an addition of around $1,000 to $2,000 to get an appliance approved for use in a particular area (e.g. Christchurch). The cost of compliance monitoring and enforcement may also be recoverable from burner manufacturers. Environment Canterbury has budgeted for compliance monitoring costs of around 100 person hours per year.
A1.3.4 Burner costs
It is likely that manufacturers would pass on additional costs associated with wood-burner production to consumers. However, in most cases the cost of research and design and the costs associated with appliance testing to the NZS 4013 criteria will already be integrated into wood-burner prices.
Currently there do not appear to be significant differences in the cost of burners meeting the 4.0 g/kg emission standard and those currently approved to the 1.5 g/kg level, with retailers in Christchurch quoting burner acquisition and installation costs starting from around $1,800 for the latter and an Auckland dealer quoting from $1,600 installed for a 4.0 g/kg burner. However, the Home Heating Association suggests a real cost difference of about $800 per inbuilt burner for a 1.5 g/kg burner compared to a 4.0 g/kg burner and a similar real cost differential for the freestanding models (personal comment, Ed Hawkes, December 2003). The $1,800 installed cost for a 1.5 g/kg burner compares to around $2,500 for a burner meeting the new Christchurch standard of 1.0 g/kg. At present there are only a small number of solid-fuel appliances approved to the latter standard, limiting the options, including the range in heat output available to consumers.
A1.4 Conclusion
The introduction of a national environmental standard of 4.0 g/kg would have some additional benefits in reducing PM10 concentrations, with an estimated 3% decrease in the health impacts of PM10 relative to the status quo option. In contrast, the introduction of a 1.5 g/kg emission standard is likely to result in significant improvements in PM10 concentrations and the associated health impacts in urban areas of New Zealand. An estimated additional reduction of 10% in existing pollution-related mortality is predicted by 2013 if a standard of 1.5 g/kg for wood burners were introduced. Based on existing information, it is unlikely that there would be additional benefits in reducing the test criterion to below 1.5 g/kg.
Costs associated with the introduction of a national environmental standard for wood burners include potential costs to manufacturers associated with appliance testing (around $8,000 per burner), appliance approval costs (around $1,000 per burner), additional research and design costs, and loss of market share for manufacturers unable to produce appliances meeting the standard. In many cases manufacturers already incur these costs, because a proportion of appliances for sale in New Zealand are already tested to NZS 4013 and administration costs are already incurred by manufacturers submitting appliances for approval for installation in the Clean Air Zones of Christchurch. Other costs associated with the introduction of a standard of 1.5 g/kg for wood burners include a possible increase in the cost of a burner of around $200 to $800 per burner, and costs associated with education, awareness and enforcement, and compliance monitoring.
