Technical, mitigation, and financial comparisons of 6 kWe grid-connected and stand-alone wood gasifiers, versus mineral diesel and biodiesel generation for rural distributed generation

This research presents a technical simulation and economic model of three small-scale technical alternatives supplying a typical rural homestead electricity load: a 15 kVA wood gasification unit coupled to a 6 kWe modified grid-connected petrol generator; the same system operating as a stand-alone system, and; a 6 kWe diesel generator, all modelled against the electricity network in the southwest (SW) of Western Australia (WA). The three technical alternatives are supplemented by a further four comparative scenarios, including zero woodgas fuel and labour costs, generous capital and feed-in-tariff subsidies, and also the displacement of mineral diesel with biodiesel. The results quantify technical outputs of the systems and also the associated financial and greenhouse gas emissions of each system and scenario. The results indicate that significant mitigation is possible from each regional household using woodgas technologies or biodiesel fuels, yet the associated costs of this mitigation is extremely high when compared to the electricity network. In light of the extremely high cost of electricity and mitigation using small-scale bioenergy systems, governments may consider re-allocation of small-scale grid-connected distributed energy support mechanisms towards larger regional bioenergy projects, or risk increasing the electricity prices for private entities and governments.

► Significant household mitigation is possible, albeit at high distributed system cost.
► Grid-connected 6 kWe woodgas systems are uncompetitive relative to the network.
► Small-scale grid-connected bioenergy generation remains uncompetitive with subsidies.
► All 6 kWe woodgas systems were more expensive than diesel and biodiesel alternatives.
► Small-scale biomass-to-electricity systems exhibit high capital and operating costs.