On a global level, the potential for renewable energy is more than sufficient, writes researcher Schalk Cloete. However, on a regional level, this is not the case, especially in developing Asia and Africa. Renewable energy technology forcing in these regions can have serious socio-economic consequences.
We often see images like the one below which imply that the potential of renewable energy is essentially limitless. Thus, if we only had the will, we could easily power the world with clean and everlasting renewable energy.
Solar PV is generally viewed as the most limitless of all the renewable energy options. The little squares on the map below shows just how easy it is to power the world with solar.
The reality is, however, that realistic renewable energy potential is some orders of magnitude lower than these simplistic illustrations.
Firstly, areas covered by urban developments, forests, protected zones, ice, dunes or rock need to be excluded. In addition, areas with excessive slope or elevation are also not eligible build sites. After these eliminations, only areas with a sufficiently strong solar irradiation and wind speeds can be considered.
From the remaining land area, only a small fraction can be used before serious social resistance or natural habitat interference is encountered. For example, only about 1-2% of available land area is covered by onshore wind in European countries like Denmark, Germany and the Netherlands, but these issues are already becoming significant.
All of these factors have recently been quantified in a very interesting study published in the Elsevier journal “Global Environmental Change”. Findings from this study are further discussed below.
Globally – more than enough
Even after all of these realistic assumptions, the total global wind and solar resource still easily meets projected demand by the year 2070 even under the most pessimistic assumptions (the dark bands in the graphs).
It is clear that PV, CSP and offshore wind hold the greatest potential. Onshore wind has a much smaller potential, especially under low (3%) and medium (6%) land availability assumptions. PV on buildings also has quite a large potential in the year 2070 due to assumptions of large urban buildouts and large gains in solar panel efficiency (35% in 2070).
The projected electricity demand by 2070 is set within the range of 24-40 GJ/person/year. For perspective, the average American currently consumes about 44 GJ of electricity per year and electricity accounts for only about 20% of final energy consumption.
Regionally – problems arise
Unlike hydrocarbon fuels, electricity is not easily tradeable between different world regions. It is therefore very important to assess renewable energy resource availability on a regional basis. The following highly informative graphic tells the story:
It is clear that only North America, developing Europe and Australia have access to a well-balanced mix of renewable energy resources with more than enough potential. A well-balanced mix of resources is important to minimize the effects of intermittency in order to allow for higher renewable energy market shares. For example, the positive effect of mixing wind and solar in terms of preserving more value with increasing market share is shown below (the y-axis illustrates the value of generated electricity where 1 is the average market value):
When deploying only wind or only solar PV, the solar PV option is especially challenging. Because solar’s variability is very pronounced and highly correlated within a reasonable distance, its value falls rapidly with increasing market share. This is illustrated below:
Offshore wind and rooftop solar are about twice as expensive as onshore wind and utility-scale PV for obvious reasons. In addition, the development of CSP has been slower than anticipated. It should be mentioned, however, that the low-cost inclusion of thermal energy storage in CSP significantly increases its value.
Given these considerations, most regions around the world will have a very tough time achieving high market shares of renewable energy. The two most populous regions in 2070: Sub-Saharan Africa and South Asia will have to rely heavily on solar power. If solar thermal technology can be greatly improved, this will help Sub-Saharan Africa, but South Asia will have to rely almost completely on solar PV – mostly the expensive distributed kind. North Africa and the Middle East face similar challenges.
The highly populous East Asian, South-East Asian and South American regions can achieve greater balance if they heavily rely on expensive offshore wind. South-East Asia will be especially dependent on offshore wind together with EU Europe.
It should be noted that further refinement of the data to a country or state level will further accentuate these challenges. The situation outlined above assumes lots of long distance electricity lines and excellent performance by politicians to establish cross-border regional electricity markets.
Special challenges for the developing world
The challenges outlined above are further augmented in the developing world, especially Asia and Africa which may well be home to 80% of the world population by the end of this century:
These regions and their enormous populations still have a lot of industrialization to do. Industrialization is critical to give these people a reasonable quality of life, to shield them against the effects of climate change, and to naturally curb population growth. Unfortunately, industrialization is also an incredibly expensive and resource intensive undertaking. Insisting on driving industrialization primarily through renewable energy will therefore come at a tremendous cost in terms of quality of life, especially given the challenges outlined in the previous section.
As a simple example, I estimated the effects of renewable energy technology forcing on economic growth in India as an example at the bottom of this article. The example showed that deployment of only solar and wind to grow Indian electricity production to support economic growth would cut the Indian growth rate in half. After 20 years of this practice, the Indian economy would literally be only half the size it could otherwise have been. This situation will be further worsened given the fact that South Asia will have to rely heavily on expensive distributed solar PV which will rapidly lose value as market share increases. Such a development strategy is simply not going to happen unless rich nations finance the necessary subsidies. And that is not going to happen any time soon.
Inefficient and disastrous
This article was definitely not written to write off renewable energy. As often stated before, I wholeheartedly support moderate wind and solar deployment in regions where they make sense. For example, the US is one country where renewable energy makes a lot of sense due to its vast available land areas, high quality wind and solar resources, and affluent population.
Wind and solar technology forcing in regions with much lower potential and much poorer populations is a completely different story though. I fear that this strategy will be highly inefficient at best and disastrous at worst.
Schallk Cloete describes himself as “a research scientist searching for the objective reality about the longer-term sustainability of industrialized human civilization on planet Earth. Issues surrounding energy and climate are of central importance in this sustainability picture and I seek to contribute a consistently pragmatic viewpoint to the ongoing debate. My formal research focus is on second generation CO2 capture processes because these systems will be ideally suited to the likely future scenario of a much belated scramble for deep and rapid decarbonization of the global energy system.”
This article was first published on our sister website The Energy Collective and is republished here with permission.
S. Herb says
Serious considerations, and the bar graphic is indeed informative. I expect that the future will include markets in solar generated liquid fuels, but that is far from practical at present. In the shorter term, regions with good insolation should be able to develop social and industrial systems which match better the solar delivery profile. Maybe not so ‘efficient’ but we in the west have developed some very bad habits during the centuries-long glut of fossil fuels.
Schalk Cloete says
Yes, some serious technological progress in electrolysis could turn places like the Middle East into a great solar synfuel exporter instead of a great oil exporter. The major problem with synfuel from solar PV, however, is the very low level of capacity utilization.
Social change to adapt to the availability of renewable energy is also an interesting discussion topic. We can definitely all live much more energy conscious lives, but it is difficult to see this happening unless the majority of people believe that this really is the only option. I cannot really see this happening any time soon.
Mike Parr says
“adapt to the availability of renewable energy”:
match PV size/output to A/C 24hr demand plus estimate for none-A/C elec (at night in the range 6 – 10kWhr). At a guess a mix of 6 – 7kWp of PV + the kit listed in the link plus say 12kwh of battery storage and in a summy location like California (or South of France, … or…) you are probably looking at 70 – 80% self sufficiency & all the kit is available right now – there is probably even a business case. Crank up elec’ prices & it will be surprising how people see the above “as the only option”.
Schalk Cloete says
I spent some time a year or two ago trying to find reliable capital costs, product lifetime and efficiency of this technology, but was not successful. Based on simple COP estimations, the efficiency should be around 70% – a bit less if heat losses and the electricity consumption from fans is accounted for. Do you have a good reference for capital costs (per kW and per kWh) and useful lifetime?
S. Herb says
Well, as a very trivial example imagine household refrigerators which build up an excess ice reserve during the day and manage without current (or almost) through the night (or even a few days with care). If inexpensive, these could be very attractive in countries with good sun and flakey grids. It’s also not a disaster if they warm up a few times per year (and who really needs air conditioning during the monsoon season). There is a high price for 99.9% reliability and much social improvement can be achieved with more relaxed standards. This may be more problematic for industrialization, but there are probably useful things to be done in the absence of massive new coal generation.
Actually, you solve this easily today: you have only to buy a little bigger frezzer or refrigerators and fill it partly with icecubes/water that keeps it cold for longer time. Put a timer on the power cord so it only runs from 9 am to 17 pm.
“The major problem with synfuel from solar PV is the low level of capacity utilization.”
The capital costs of P2G is not high and those plants are unmanned. So why would that be such problem?
I estimate that the production costs (€/MWh produced) is the critical factor. And those are already near ~3cent/KWh in Qatar, etc. Decreasing further towards 1cent/KWh
Schalk Cloete says
Projected costs of future PEM electrolysis technology comes in at about €800/kWH2. This is not so much, but if you say that electricity will come from peak solar PV (probably less than 4 hours per day on average), this cost blows up to €4800/kWH2 – roughly the cost of a nuclear plant.
Hydrogen distribution and storage costs are also quite high. If the hydrogen is only being produced for 4 hours per day, this capital will also become very expensive. Alternatively, the hydrogen can be used to make hydrocarbon synfuels or ammonia, but this will add additional costs.
derek clements-croome says
Very informative.Have you updated to 2018 onwards but I suspect they are the same.
I want to reference these what is the citation I should use to give you full credit?
Steven Runfola says
“Firstly, areas covered by urban developments ……must be excluded.”
Why? Solar power generation is and will be used extensively in areas with urban developments.
Schalk Cloete says
This statement does not include rooftop solar PV (the red bar in the graphs).
Cost is almost entirely labor costs.
The thing developing economies need is jobs.
The economic policies for developing economies nend to be like those of China for decades, manufacturing and constructing using local labor. An African nation might be better off using obsolete cast off manufacturing equipment from a developed nation to manufacture solar cells, starting say in 2000 on the production experience curve to leverage lower local wages in a labor intensive obsolete cell assembly into panels.
More important than the products themselves is the experience gained in manufacturing, marketing, and construction of finished capital with end to end finance – the entire value chain.
Whether wind or solar or batteries, the industry has evolved to modular standards so different generations and sources of components can be mixed and matched.
Cost becomes jobs and worker income. Income is the means to pay for the energy produced.
Are Hansen says
The interesting point in this article is that available land area varies greatly around the world, and therefore the space available for utility scale solar and hydro.
But the rest is way to pessimistic – 2070 is far away! Anything could happen by then, both technologically and socially/politically. Estimating only a 35% conversion efficiency of solar PVs in 2070 is very unlikely. By then, PVs will certainly not be made from super pure silicon wafers anymore, but be super cheap and pliable, covering not only rooftops, but entire building, cars, etc.
Reliable estimates 54 years into the future is impossible. It’s like saying in 1962 that by 2016 vacuum tubes could be made so small that a computer could possible fit in a car…
Schalk Cloete says
The main issue here is not insufficient solar PV potential (aside from Europe). The issue is more with wind – which can scale to higher market shares without losing too much value, especially when combined with solar PV.
I agree that these kinds of long-term studies will be wrong in many ways, but they do give some valuable insights that are often overlooked by renewable energy advocates.
Are Hansen says
I appreciate you trying, but you failed – as would all the rest of us in an impossible task. Let’s stick to things that are within reasonable possibility to say anything about. Detailed numbers and graphs about the world in 54 years are ridiculous
Mark Roest says
We already see batteries at 180-200 Wh/kg, and as low as $145/kWh capacity (LG Chem to GM). Stanford’s Professor Cui has small-scale commercialization of 300 Wh/kg using graphene cages to keep Si fragments in contact with each other after Li goes in and out a few times. We will see $100/kWh and >200Wh/kg batteries in mass production well before 2020.
There are available, but not yet commercialized, improvements for wind turbine design that will very likely cut the levelized cost per kWh in half within 5 years. The batteries will realize the full economic potential of intermittent solar, wind, etc., so they earn more money per kWh and can spread 1 to 2 orders of magnitude faster.
That is cheap enough and close enough and dense enough to plan for a total disruption of internal combustion by batteries in the transportation industry, and of fossil and nuclear fuels for electricity by renewable energy and batteries, within 10 to 15 years, relying on a combination of capitalism and economic policy decisions.