All technologies have their own footprint. Renewable energy sources are generally cleaner, more sustainable and better for social development than fossil-fueled alternatives. As with any technology there are pros and cons to the use of renewables. Our report “Renewables on the Rise” clearly showed the benefits of renewable energy development. In this blog, author Hans Verolme looks at potential risks and problems associated with the large scale development of renewable energy technologies.
Water and wind power have been in widespread use for centuries. Since the 1880s hydro-power from dams has been harnessed for electricity generation and has provided a significant share of electricity production worldwide. Until the Second World War, windmills were widespread in rural areas for pumping water, but they were rarely used for power generation. Only since the 1973 oil crisis have wind and solar energy gained ground. These renewable technologies struggled to grow their market share due to relatively low efficiency and high upfront investment costs. Over the past decade, we have witnessed a revolutionary transition with the price of wind energy and solar photo-voltaics now at or near grid parity. Four decades of public investment in R&D have fueled innovation with a focus on improved efficiency. Public support for small-scale and community-owned generation through e.g. feed-in tariffs have contributed to this silent revolution.
Traditional critiques of renewables have focused on the intermittency of wind and solar power and their high upfront investment costs. As the use of renewable technology became more widespread, research and development turned to addressing intermittency through new energy storage and smart grid solutions. In Germany today, with 25% of electricity generated by grid-connected renewables, grid stability is not a problem.
Today, we are most critical of the further development of large hydro-power dam projects and the development of biofuels as an alternative to fossil fuels.
Historically, hydro-power generated by large dams has become associated with negative social and environmental impacts. A dam interrupts and can permanently decrease the flow of the river, which often harms the ecosystem. Lack of consultation of affected communities has been the norm. Flooding a basin often leads to loss of fertile land. Forced relocations have led to human rights abuses. Many of the affected communities have literally seen development pass them by. This led to a strong and growing anti-dam movement. In response to the loss of public support for hydro-development, the independent World Commission on Dams in 1998 prepared stringent recommendations for any further hydro-power development. Unfortunately, the sensible recommendations of the WCD have been treated as optional by governments and business. We observe a trend towards more investment in small and in-stream hydro-power projects with a small footprint. Opposition to mega-projects remains strong and investments have decreased.
Increasingly, old large hydro-power dams are being redeveloped after several decades of use. The dams have often seen capacity drop significantly due to siltation of the basin. The redeveloped dams can be fitted with the latest generation efficient turbines. At the same time, large dams are sensitive to climate change. The flow of rivers is disproportionally affected by a drop in precipitation. As a result, power generation becomes less reliable and redevelopment uneconomical.
Biofuels and biomass
Many conventional coal-fired power plants use biomass or municipal waste to co-fire their plants. Similarly, many waste incinerators need biomass to operate and generate heat and power. Co-firing of biomass from often poorly managed forests to make the energy mix more 'green' is plain wrong. The use of municipal waste can also deprive communities of waste pickers of their livelihood, or biomass from supposedly 'marginal lands' deprives herders from traditional sources of fodder. Furthermore, incineration is a major source of toxic air pollution.
Biomass and biofuels have incorrectly been characterized as carbon-neutral. Cultivating, harvesting and transporting biomass also generates a considerable amount of emissions. Processing or incineration of biomass and biofuels often produces dangerous gasses, such as NOx, carbon monoxide and soot.
Biofuels are expected to gradually replace fuels from oil. The first generation of biofuels are made from sugar, starch or vegetable oil, all agricultural products that compete for valuable arable land with food crops. They also need clean water and other inputs, such as fertilizers and pesticides, to grow. These agricultural inputs require significant energy and resources in their production. The risks and opportunities of biomass are explored further on p. 31-33 of our report “Renewables on the Rise.”
Wind energy does not leave behind a scarred landscape, like a coal mine. Yet, its growing impact on the landscape and wildlife has been closely scrutinized by conservationists. Like other large scale development projects, wind and concentrated solar projects require environmental impact assessment. The siting decisions need to take into account migration routes of raptors, potential noise impacts on bats and, in the case of offshore parks, the potential impact on marine and migrating birdlife. Interestingly, as wind mills have grown in size and capacity (the largest mills a rated between 3 and 5 MW with 50% net capacity) designers were forced to change the blade design to make them lighter and less noisy. In Europe many farmers happily agree to leasing a corner of their fields to a windmill, bringing an additional revenue stream with little risk on their part.
Some privileged communities oppose wind parks in scenic landscapes, arguing they are ugly or devalue their land. This is called NIMBYism (from: Not In My Back Yard). Fact is that land ownership and access and usufruct rights need to be respected in project development, something many development initiatives have ignored in the past. Beauty is in the eye of the beholder. For someone growing up around windmills this criticism sounds far fetched.
Non-renewable resources for renewables
Finally, we sometimes forget that even clean technology may require resources that are not, yet, sustainably produced. The manufacturing of solar panels, for example, requires rare, often times toxic, metals which cannot be acquired from sustainable sources. Wind turbines are made using copper and rare earth metals. These can however be recycled once the turbines have come to the end of their productive life. Designers now use cradle-to-cradle design processes to reduce the footprint of products, reuse materials and mimic biological processes in an effort to prevent waste. There is a long way to go.
From this brief overview it becomes evident that our consumption of energy, even with clean renewable technologies is not without consequence. It is important to understand that long-term sustainability can only be achieved by avoiding energy use. Avoiding comes before reducing one’s footprint by using only the cleanest and most efficient technologies. This may sound odd in a world where billions lack access to even the most basic energy needs. Indeed, this is not an argument against the concerted campaign to bring clean power to all. The potential for long-term sustainability lies with the rich, regardless where they live, who take much more than their fair share. It is over-consumption of dirty energy that is the problem.
 Grid parity occurs when an alternative energy source can generate electricity at a levelized cost (LCoE) that is less than or equal to the price of purchasing power from the electricity grid. The levelized cost is the price point at which a project breaks even over the lifetime. This economic assessment includes all costs over the project lifetime: the initial investment, operations and maintenance, cost of fuel and cost of capital. LCoE excludes the social cost of pollution. The wholesale purchasing price of fossil-fueled electricity can also be reduced by direct or indirect subsidization.