Zero Carbon Emissions Plans (ZCEP)
To reach a target you need a plan. To build developments or organisations that are or become carbon neutral or carbon positive you need a plan.
A Zero Carbon Emissions Plan (ZCEP) should be prepared for all building or asset developments, or organisations, where energy will be consumed in the operation of that building or asset. LID Consulting can assist with this, in puling together the plan and the modelling.
A Zero Carbon Emissions Plan should show how the building, asset or organisation will facilitate reducing operational emissions over an agreed time-frame. This time-frame commitment is 2050 for the Victorian and NSW State governments, which is a good start. Where possible developments and organisations should aim to reach this point sooner, perhaps 2025, 2030 or 2040.
Reducing carbon emissions to zero by 2050 is a commitment to reduce emissions from 100% over 30 years. This equates to a reduction of 3.3% on baseline modelled (proposed) or actual energy figures in 2020. A commitment to reduce emissions to zero by 2040 equates to a reduction in emissions of 5% per year. These options are not a challenging commitment. In recent school projects we have worked on, commitments for installing PV panels will reduce electricity consumption by 17% in one year.
Guidance to assist in preparing the ZCEP:
- Typically, the starting point is to maximise energy efficiency of the building or asset. Realistic opportunities must be taken. Where the starting energy consumption is smaller, then the absolute reductions in future years will not need to be as significant.
- An estimate should be undertaken of the likely energy consumption of the proposed or upgraded development or organisation. Knowing the starting point for emissions, allows planning what reductions need to occur to meet the target.
A typical Net Zero CEP for a building would demonstrate the following:
- Maximise the energy efficiency of the building fabric
- Maximise passive design or other energy efficiency strategy such as designing to passive house principles*.
- Optimise building envelope insulation, glazing, shading, sealing.
- Maximise the efficiency of building systems
- Minimise energy consumption of services through highest efficiency HVAC, lifts, appliances, equipment, etc.
- Identify alternatives to the use of gas e.g. in cooking, hot water production, heating/cooling.
- Select optimised electric hot water service solutions or solutions that can be upgradable.
- Quantify expected energy consumption – Prepare an estimate of energy consumption when the building is in use.
- Identify potential on-site renewables opportunities – optimise roof top solar and allow for Building Integrated PV (BIPV) panels or other on-site renewables such as geothermal or wind. Design to accommodate the renewables now or in future.
- Include cabling for electric vehicle recharging.
- Purchase green energy and / or carbon credits to offset any shortfall.
Note: as the state electricity grid moves to renewables at the identified goal rate (50% by 2030), then the balance of non-renewables that would need to be offset by purchasing green energy will reduce into the future.
* Five principles of Passive House design (applicable for Melbourne):
- Insulation – higher levels use BCA standards x 150%
- Window U values 1.3 – double glazed low e (Passive Haus warm temperate zone)
- Heat recovery unit >75% efficiency. Use certified Passive Haus units. Ventilation units consume a similar amount of energy use as a light globe. Filters to be changed once every 12 months.
- Airtightness – Airtightess <0.6 ach (air changes per hour). Design an un-interupted insulation barrier around the building fabric. Junctions of elements are the most challenging locations. Measure with a blower door (pressurisation test). Needs to be <0.6 ach. The AusZEH House achieved 4 ach. Average of Aus houses built in last 15 years 15 ach.
- Thermal bridge free design – This is also a new requirement of the BCA 2019. Psi value measures speed of thermal bridging. Psi<0.01W/mk considered thermal bridge free. Design to avoid thermal bridging through timber studs. Add an internal layer for services so these do not bridge the insulation.
In Melbourne this means:
- 80-90% less energy use than most blgs. Equiv to approx 8.5-9.5 stars
- Heats or cools required ventilation – no more
- Heating <10W/m2 Cooling <10W/m2
- For Passive Haus certification Primary energy (energy required to run everything in the blg incl heating/cooling, HWS, lights, power etc) needs to be <120kWh/m2.annum ie more than just NatHERS.
- Alternative energy not required under Passive Haus classic accreditation
- Low area/volume ratio – good to be <0.7 will help
- No open chimney
- Lager openings to the sun, smaller away from the sun
- Use Passive Haus certified components eg certified heat pumps