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Environmental Aspects and Impact Assessment Introduction This page includes a brief description of the requirements for Environmental Impact Assessments, and a full indicative assessment of the environmental impacts of a typical small scale biofuel - fuel cell energy system. The environmental performance results from this assessment are used in our Environmental Impact Assessment method to give an overall evaluation of the environmental impact. Finally, a review of our assessment approach is given. Requirements for Environmental Impact Assessments Environmental impact assessments are required for any projects likely to have a significant effect on the environment, and are mandatory for large energy projects and wastewater treatment plants. Planning authorities require the developer to produce an Environmental Statement including:
Consideration of the alternatives provides an opportunity to "design out" adverse environmental effects at an early stage: prevention of adverse environmental impacts is better and more effective than mitigation or remedy at a later stage. |
Index of technical reviews |
Description of the development
The performance assessment is undertaken for a typical small scale (<1MW) local energy system, using one of the following biofuels probably with a make up supply of natural gas, and a fuel cell system to provide electricity.
Biofuels considered:
Environmental aspects and significance
Environmental aspects are considered under the following headings:
The significance of all aspects are considered relative to the other aspects and assigned a weighting using the Environmental Impact Assessment method. The weightings are given in the spreadsheet.
Environmental performance
In this indicative study, the performance of the system concept is assessed in terms of the potential global impact. More detailed investigation and forecasting would be required for specific projects, especially with regard to local impacts.
| Environmental aspect | Environmental performance | Typical score |
| Social inclusion | ||
| Meet growing energy demands in developed world | Potential to supply a small proportion of domestic energy demand | 1 |
| Meet growing energy demands in developing world | Potential to supply a high proportion of domestic energy demand, widely applicable | 3 |
| Development of energy infrastructure in developed world | A component of renewable dispersed generation | 1 |
| Development of general infrastructure in developing world | Provision of electricity and potential for integrating general infrastructure improvements in projects | 3 |
| Accessibility of technology | Currently poor due to lack of commercial availability and information but potentially good | 1 |
| Economic development | ||
| Affordability | High price of fuel cells initially. (Only affordable for high value markets or small scale niche market applications - not biofuels) High cost of digester or fermentation vessels and fuel processing equipment | 0 |
| Return on investment | Low due to high price initially. Capital better invested in alternative energy systems initially. | -1 |
| Risk of increased costs or loss of income | Low risk, small scale applications | 2 |
| Resource use | ||
| Depletion of non-renewable energy sources: Consumption of fossil fuels | Reduction of fossil fuel consumption by substituting biofuels, although make up fuel will probably be required from fossil fuel sources. Efficient conversion with no distribution losses. | 2 |
| Use of limited renewable resources: Consumption of biofuels | Care required to ensure use of biofuels is within renewable capacity and allows for competing uses. Efficient means of conversion | -2 |
| Depletion of material stocks: Rare metals | Platinum catalysts: 3.7%pa increase in demand due to existing uses: 49% jewellery (increasing), 31% auto catalysts (reducing), 24% process catalysts & computer disks (increasing). 225 years life index. A substantial increase in demand is forecast with the commercialisation of fuel cells but the high price encourages development of lower platinum loading. | -1 |
| Nickel catalysts: Existing uses: 76% corrosion resistant alloys, 20% electroplating. 52 years life index. Although reserves are limited, use of nickel as a catalyst in fuel cell systems could reduce demand if they replaced turbines using nickel alloy components | ||
| Zirconia electrolytes: Existing uses: >90% Zirconium metal in nuclear reactors and fuel elements, corrosion resistant alloys for chemical plants, superconductors; Zirconia oxide ceramic used as foundry sand and refractory material. Rare as metal but zirconia oxide exists in beach and stream sands. | ||
| Provision of drinking water | Water emitted by fuel cells is very pure and suitable for drinking. Most of the water is recycled internally for steam reforming so quantities emitted are very low. | 0 |
| Provision of sewerage | Extracting energy from biogas may encourage use of digesters for sewerage and farm slurry. In developed areas digesters may be superseded by tertiary treatment or the difficulty of disposing of sewerage sludge. | 1 |
| Land use effect on urban development | Small scale CHP may reduce the necessity for upgrading urban distribution networks, and micro scale CHP using fuel cells at individual dwellings may reduce the requirements for local heating mains, otherwise required for community CHP. Use of biofuels will require biogas mains. | 0 |
| Land use effect on agriculture or forestry | Farm slurry sludge is a valuable organic fertiliser after digestion. It is technically feasible to use sewage sludge but this may be socially unacceptable. Energy crops for liquid biofuels take agriculture or forestry land. Reduced requirement for electricity transmission may reduce area cut from forestry. | -2 to +1 |
| Water use effect on agriculture and aquaculture | Energy crops for liquid biofuels may use large quantities of water which are not recovered | -3 to 0 |
| Land & water use effect on recreation & tourism | No significant effect except visual impact covered below | 0 |
| Transport | ||
| Depletion of fuel stocks & impacts of transport fuel processing | Local fuel supply. No bulk transport required. | 0 |
| Global warming emissions arising from transport | Negligible transport required | 0 |
| Local health effects and disturbance arising from transport | Negligible transport required | 0 |
| Land use, materials use & waste arising from road construction | Small scale schemes requiring no additional access roads | 0 |
| Ecological protection | ||
| Global warming emissions from use of fuels: | ||
| CO2 emissions | CO2 emissions less than combustion engine systems due to higher efficiency | -2 |
| CH4 emissions | CH4 emissions from digestion of biofuels reduced, especially from farm slurry | 3 |
| Global warming emissions from construction activities | Fuel cell system manufacture & delivery. Construction of digesters or fermentation vessels on site. | -1 |
| Hazard to biological life cycles or ecosystems: | Low hazard | |
| Acid rain: SO2 emissions | Biogas and landfill gas cleaned of SO2, giving near zero emissions | 0 |
| Acid rain: NOx emissions | Near zero emissions | 0 |
| Hazard to range of natural species or biodiversity | Small scale schemes. Care required if energy crops replace natural habitats | 0 |
| Damage to wildlife habitats | Small scale schemes. Care required if energy crops replace natural habitats | 0 |
| Soil erosion | Reduced desertification due to reduced global warming. Use of digested sludge as fertiliser reduces soil erosion. Care required to ensure energy crops do not replace wind breaks | 2 |
| Environmental protection | ||
| Visual impact | Scaleability & flexibility of siting mean fuel cell systems can be installed to reduce visual impact. Small scale digesters may be buried or hidden at sensitive sites | 0 |
| Effect on built environment | Scaleability & flexibility of siting mean fuel cell systems can be installed to suit building protection constraints. Digesters situated at sewage works | 0 |
| Effect of extraction processes | ||
| Fossil fuel extraction & processing | Make up natural gas required. Low impact compared with coal mining & oil refining | -1 |
| Rare metals mining | Low quantities required for catalysts | -1 |
| Effect of disposal of wastes: Waste arisings | Reduced mining waste (compared with coal or bulk metal mining), reduced agricultural waste, reduced sewage sludge if can be used as fertiliser | 1 |
| Land & ground water contamination hazard | ||
| Liquid chemicals | None from operation, none known from manufacture | 0 |
| Toxic metals | Fuel cell / reformer manufacture and recycling: Nickel compounds arising from extraction, processing, or disposal have high toxicity and are carcinogenic. Recorded cases limited to nickel mining and processing workers. Care to be taken in all preparation and disposal processes | -1 |
| Water pollution & water quality | ||
| Chemical pollution | Digestion of sewage an intermediate form of treatment. Farm effluent reduced by digestion of farm slurry. | 1 |
| Flow and temperature effects | None | 0 |
| Air pollution & air quality | ||
| NOx emissions | Near zero | 0 |
| SO2 emissions | Near zero | 0 |
| CO emissions | Near zero | 0 |
| Volatile HC's emissions | Near zero unless liquid biofuels used | 0 |
| Particulates | Near zero | 0 |
| Noise | Low noise | 0 |
Environmental impact
The results of the assessment, using the above performance scores in the assessment method, are given in full in the spreadsheet. The total score is 59, which being positive, shows an overall benefit of the scheme. The assessment could be used for alternative schemes and the scores compared.
The significant positive environmental impacts of the scheme are:
Neutral impacts include:
The main significant negative impact is the emission of CO2 which causes global warming. However with farm slurry digester schemes or other methane capture schemes there should be a net positive impact on global warming from the scheme due to reduced methane emissions. CO2 emissions are lower using fuel cell systems than any of the combustion engine systems.
Significant adverse impacts
As stated above, the main adverse environmental impact is global warming from CO2 emissions. Improvement actions include:
Review of the Environmental Impact Assessment method
The main comments are:
Details on using the assessment method are given on the Environmental Impact Assessment method page.
References
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