A new study published in Energy Strategy Reviews this month affirms that sourcing 95 percent of our energy from sustainable sources by 2050 is possible, using already available technologies. The authors are from the Dutch renewable energy consultancy Ecofys. Their paper includes technical detail, but the general salient points are well identified and clear to the non-expert reader. Familiar themes are sounded and buttressed with careful and sensible analysis.
Efficiency and electrification are two key requisites on the way to the 2050 goal. The scenario proposed by the study envisages a slightly lower power demand in 2050 than in 2000, even allowing for established forecasts of population growth and GDP growth. It surveys demand under three sectors – industry, buildings and transport – indicating in each case the prospects of much lower demand from the application of efficiency measures as compared with current business as usual (BAU) practices. The electrification which plays an important part in lowered demand occurs primarily in the buildings and transport sectors.
In the buildings sector the paper envisages the retrofitting of existing buildings by 2050 to ambitious energy efficiency standards. This requires retrofit rates of up to 2.5 percent of floor area per year, which is high compared to current practice, yet feasible. For new buildings the scenario is for an increasing percentage to be built to ‘near-zero energy use’ standard, reaching a penetration of 100 percent of new buildings by 2030.
The power reduction in the transport sector scenario is not derived from a reduction in activity. It depends primarily on the reduction of energy intensity through the most efficient technologies. Plug-in hybrids and/or electric vehicles are posited as the primary technology choice for light duty vehicles. Long distance trucks undergo large efficiency improvements, but not electrification due to the prohibitive size and weight of batteries under current technology. A small share of shipping fuel is considered replaceable by hydrogen won from renewable electricity.
Global energy demand in all sectors when split by energy carrier shows a large increase in electricity but a sufficient fall in other carriers to add up to a projected total energy demand in 2050 slightly lower than that experienced in 2000. This stabilisation on the demand side is essential to the goal of having renewable energy provide nearly all of our energy needs by 2050.
Turning to the supply side, the paper considers the realisable deployment potential of the various renewable sources. The growth of on-shore wind power has been remarkable in the last decade, with annual growth rates exceeding 25 percent in most years. Several off-shore wind parks are already in operation worldwide and many more are currently in planning phases. The paper settles on annual growth rates of ∼30 percent for off-shore wind and nearer 20 percent for on-shore wind.
Future hydropower growth is restricted in the scenario to small hydropower and efficiency gains in existing large hydropower schemes in the interests of respecting existing ecosystems and human rights. The wave and tidal energy potential is estimated at around 5 percent of the potential of offshore wind.
Direct solar energy is seen as having the largest realisable technical potential for renewable power and heat generation. The scenario assumes a photovoltaic growth rate of 25-30 percent per annum and a concentrating solar power (CSP) growth of 20 percent. Concentrating solar heat technology is not yet on the market and is therefore included only at a very small potential, around a tenth of the potential of CSP.
Geothermal energy has not had the attention it might have and given its large potential, specifically for demand-driven power, the scenario premises that the current 5 percent annual growth rate could be doubled to reach the levels of other renewable power options.
Bioenergy is included in the scenario only to the extent that it is sustainable and leads to high greenhouse gas emission savings in comparison to fossil references.
Thus efficiency on the demand side combines with the strong growth of renewable options on the supply side to reach the goal of a sustainable energy system by 2050. The writers note that their scenario uses only a small fraction of each of the sustainable sources.
The study then proceeds to stress the importance of a number of enabling levers: grid capacity improvements to remove bottlenecks and increase transmission capacities; demand side management, particularly for wholesale customers, but also at individual consumer level; storage, in the form of pumped hydro, centralised hydrogen storage, battery and heat storage; conversion of excess renewable electricity to hydrogen for use as a fuel in specific applications.
Overall, the energy scenario would lead to a ∼80% decrease in energy-related, global CO2-equivalent emissions versus 1990 levels by 2050.
How do the cost and savings of this energy system compare with a BAU energy system? The transition to the proposed energy system would require large additional upfront investments, albeit estimated at less than 2% of global GDP at any given point in time. However in the later years the net financial impact would be positive. That is to say, the energy system proposed in this scenario would be significantly cheaper to operate by 2050 than a BAU system.
The scenario represents a radical change from current systems of energy use, and current policies will not be able to manage it. The study is clear that new policies will be required. Public bodies should create the long-term framework enabling the transition and provide investment in large infrastructure and early-stage R&D projects. Private actors should operate under a long-term perspective, resulting in adoption of best practices in energy efficiency, and should channel investments into the most efficient and sustainable energy options. The most pressing policy needs are those related to what the study identifies as the two key enabling factors for the scenario – strong energy efficiency measures coupled with electrification for remaining demand, and the preparation of our energy grids to cope with the increasing demand for renewable electricity.
So yet another welcome report says it’s feasible that we can successfully move to an economy powered by renewable energy. That doesn’t mean we will do it, of course. Policy is the crux and there are few signs that policy makers are ready for the kind of drive needed to get the change of direction under way. Here in New Zealand the government still places considerable economic hope on fossil fuel exploration.
As I was finishing this summary of the Ecofys paper the Herald and Stuff websites carried reports from the Petroleum Summit meeting in Wellington that senior figures from the oil industry and the Crown’s resource management unit are planning a public relations push to get New Zealanders supportive of oil exploration. The Minister of Energy addressed the conference in no uncertain terms: “We like you. National likes you and we like what you do.” The incoherence of the government position was echoed by other speakers. Shell New Zealand chairman Rob Jager: “We are as committed to a cleaner future as many people who protest against our activities but the reality is demand for energy continues to grow.”
Taranaki Regional Council Chair Basil Chamberlain encapsulated the contradictions: “In short, putting greenhouse gas emissions arguably aside, at this regional scale, across land, freshwater, air or coastal resources, the industry has negligible adverse impacts.”
How on earth can greenhouse gas emissions be put aside when considering the impacts of the oil industry? They are the very reason why we need to start forsaking fossil fuels and moving with all possible speed to renewable sources of energy. The Ecofys analysis, along with many others, shows the feasibility of our doing so. Governments and industry need to stop prevaricating and commit to the new course.