Human settlements

Renewable energy

Solar photovoltaics 05: Citipower's 100 rooftops photovoltaic program

Renewable Energy Commercialisation in Australia, Australian Greenhouse Office, 2003
NOTE: The status of these projects will have changed since the time of publication, and project contacts may also have changed.

CitiPower's offer to its customers of a subsidised rooftop photovoltaic power system will help promote Australia's renewable energy industry.

One of Victoria's major retail energy providers, CitiPower, is installing a rooftop-based photovoltaic (or solar generated) system across Melbourne under its 100 Rooftops program. The project was awarded a $60,000 grant by the AGO under its Renewable Energy Industry Program which aims to encourage the development of an internationally competitive, Australian renewable energy industry that will reduce greenhouse gas emissions. CitiPower has used the grant to offer its customers a subsidy for the photovoltaic system. The company believes that more affordable residential solar generation will boost consumer awareness of the benefits of accessing renewable energy.

PV Panels

In addition to the AGO rebate, CitiPower is offering customers the chance to save 35 per cent off the normal costs of installing the systems. To date, customers have been saving anywhere between $6,500 and $17,500, depending on the system and its capacity. As the systems have an anticipated 30-year life and can save the householder as much as $250 per annum on power bills, the scheme is attracting considerable interest.

The average Australian household is responsible each year for energy consumption equivalent to 8 tonnes of greenhouse gas emissions. CitiPower believes that programs like this can reduce the emissions by as much as 2.6 tonnes of coal-generated electricity per annum.

In demonstrating the viability of photovoltaic electricity for domestic and small-scale commercial applications and schools, 100 Rooftops is using Australian technologies. The technologies involve an 'interactive inverter' that eliminates the need for batteries to store the solar energy. This reduces both cost and maintenance requirements as the inverter simply returns excess power to the grid.

In the industry this system is referred to as nett metering and it is used in conjunction with the householder's normal mains power. During periods of high demand additional electricity is sourced from the grid; when supply from the solar panels exceeds demand, the owner's electricity meter runs backwards as power is returned to the grid.

The project's scale has enabled CitiPower to introduce standardsize packages for rooftop photovoltaic systems ranging from 500W to 2kW systems. The standardisation, combined with bulk purchasing of Australian systems, has enabled CitiPower to considerably reduce the cost of the unit.

Systems typically consist of 6 to 24 photovoltaic panels (or arrays) totalling up to 20 square metres, usually mounted on a northfacing roof. Total peak generating capacity of the larger arrays is 2kW. On average, a 20 square metre array produces 5.5kWh of electricity per day. The same system would reduce an annual electricity bill of $500 by about half and result in 80 tonnes less greenhouse gas emissions over its lifetime.

The project is producing a range of benefits. Its size has led to the development of innovative new products, and CitiPower has been able to provide specialised training for installing the system- positive steps for the emerging renewable energy industry. The system is also adding value to the houses in which it is being installed. Moreover, the owner benefits from a reduced bill, and CitiPower obtains more of its electricity from renewable sources.

The target is to install 100 rooftop systems, which would reduce annual greenhouse gas emissions by 130 tonnes and generate $1,000,000 worth of sales for the Australian renewable energy industry.

For more information please contact

Mr Peter Zwack
Program Manager
Environment and Renewable Resources
628 Bourke Street
Melbourne VIC 3000
Tel (03) 9297 8900

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