100% Renewables - Cost and Timescale to Transition

Climate alarmists tell us that we in order to stave off disaster we need to transition to 100% renewable energy in a relatively short time. Estimates vary, but typical timescales quoted are from ten years to thirty. So, what I'd like to do here is to get some idea of whether that is feasible, and how much it is likely to cost.

Public opinion seems to be very optimistic on this point, quoting press releases of the kind that on a certain day, most of the electricity in a certain country came from wind turbines. Or, that the latest bids for wind energy strike prices were cheaper than those for coal. If you were to take these at face value, it might well seem that it's not far from done and dusted, and that no sensible person would oppose further deployment of wind and solar energy..

For example:

The share of renewable power in global power generation reached nearly 8.4% in 2017, almost doubling in five years from 4.6% in 2012. Renewables accounted for 12% of OECD power generation in 2017, compared to 6% in the non-OECD. While the aggregate shares remain low, for some individual countries renewables now contribute a significant share of power. Countries where renewables contribute more than 20% of the power generated include: Germany, Spain, UK, Italy, Portugal, Denmark, Finland, Ireland and New Zealand.

This sounds like a fantastic result, and surely it's a reason to put plenty of funding into wind turbines and solar panels.. isn't it? Well you'd think so. Is that a realistic assessment of the situation, though?

Then again, quoting Wikipedia:

Mark Z. Jacobson, professor of civil and environmental engineering at Stanford University and director of its Atmosphere and Energy program, says that producing all new energy with wind power, solar power, and hydropower by 2030 is feasible, and that existing energy supply arrangements could be replaced by 2050. Barriers to implementing the renewable energy plan are seen to be "primarily social and political, not technological or economic"

Whilst this sounds really encouraging news, I suggest that the reader look-up Jacobson's bio on Wikipedia before deciding if he qualifies as an impartial authority on the matter. This is something you will encounter a lot, that the press releases you see are almost all by promoters of wind turbines. 

If we are to form an unbiased and realistic opinion on this, we need to go right back to original data.

First thing we need, if we are to make a reliable assessment, is a reliable source of information. Sounds obvious, but like I say a great many of the press releases you see in the news are based on figures published by the bodies with vested interests, either in selling barrels of oil, or selling wind turbines.The subject has become so politicised that it's hard to be sure of anything you read. 

Added to this, there are countless websites giving only installed capacity figures for wind and solar, and claiming these as a huge success. The problem here is that installed capacity tells us virtually nothing about how much energy these installations provide to consumers.

One site that does give comprehensive figures for real, actual energy delivered is OurWorldInData, and we shall mostly use their figures here. The site has cross-references stating where they get their figures from.


We also need to be clear about what we mean by renewable energy. There being just about as many definitions as letters in the phrase. For a start, let's be clear that here we mean world energy, which is not the same thing as world electricity. Energy includes such things as heating, transport fuels and power for industrial processes. The quote above, although it does not actually say so, refers to electricity. So rightaway we can see that it is not a realistic assessment of our ability to replace carbon dioxide emitting energy usage, of which electricity is only a small part.

Sources of renewable energy might or might not include:

  • Hydropower
  • Wind energy
  • Solar PV energy
  • Biomass
  • Geothermal
  • Wave & tidal
  • Nuclear (possibly)

Herein lies the problem, and the reason why estimates vary so widely. Most analyses include wind, solar, wave energy and  and geothermal. Some may include biomass, others may include hydro. Most do not include nuclear, but some may.

Let's take a look at the renewables market on its own. No fossil fuels here, and no nuclear. We do include hydro, though.

What we see is that wind and solar are minor players even in the renewables field, let alone in overall energy usage. Solar in particular, whose contribution is so small as to be negligible. Not quite what the press release suggested, eh?

So - Before you draw any conclusions from a press release, always check what renewables are included!

The page may be headed with a photo of a wind turbine, and may be an outright advert for wind energy, but the performance figures it quotes may include other renewables. This really is a mite scurrilous. Put it this way, if VW were including Tesla's exhaust emissions figures with their own to make their products seem better, I'm sure there would be outrage. When a wind turbine seller does effectively the same thing, it's seemingly regarded as OK. Well.. I for one don't think it is OK.  

"Today, traditional biofuels remain the largest source of renewables, accounting for 60-70 percent of the total. Traditional biomass remains the dominant fuel source for cooking & heating across many low-income households. The World Bank reports that only 7 percent of the world's low-income households have access to clean fuels and technologies for cooking; the average share in Sub-Saharan Africa was 13 percent; and approximately one-third in South Asia." OurWorldInData.

By contrast, the Fraunhofer Institute's plans for total decarbonization of energy supplies rely principally on a massive expansion of Germany's already large wind and solar industry. This approach is echoed in most documents promoting a transition to renewables, and it flies in the face of the stark fact that wind and solar's contribution to world renewable energy - let alone total energy usage - is still miniscule in spite of long term heavy investment. We already know that the German government is unlikely to approve these plans, nevertheless they serve to highlight the issue of pipedreamer claims being made for wind and solar energy.

Where the Money Goes..

Now let's take a look at how much money is being spent on each renewable technology. In view of their greater actual success you'd think the sensible thing would be to spend our money on hydro and biomass.. right?  Wrong. Well, at least that might be the sensible thing, but it's not what we're doing.

What we see is that by far the lion's share of all renewables spending goes into wind and solar installations, and indeed this has been the case for many years. Spending on some other renewables has even reduced, whilst that on wind and solar has increased by leaps and bounds. This in spite of the fact that other renewables have historically given a better, indeed much better, return on investments. Why, you may ask? What is it about these two products that induces governments to spend huge amounts of taxpayers' money on them, if the returns are so meagre?

The only rational answer is that clever advertising has swayed the minds of decision makers in this direction.

You may well ask at this stage, couldn't we just switch the funding to hydro and biomass? Well, maybe we could, but two concerns arise. Hydro is an ideal renewable, being both reliable and cost effective. Its downside is in being geographically limited, not all regions having suitable sites. -To make hydro work well, you need not only a plentiful supply of water but also a decent change in height between reservoir and turbine hall. Because hydro always has been a good option since long before climate change concerns arose, the best sites have already been exploited. Thus, funding may not be the main limiting factor in hydro development.

Biomass is inexpensive and reliable. However, its green credentials aren't exactly untarnished. If allowed to proliferate beyond the point of sustainability, it can easily become a major source of environmental damage. There are already such concerns over the larger-scale operations on the go today.

None of this alters the strange fact that most of the renewables money is currently being allocated to two of the worst-performing of all renewables.

Going for the magic 100%

In order to make some kind of projection as to how long it might take to go 100% renewable, we firstly need to examine the overall energy market including all sources, and what the rate of uptake of renewables has been over recent times. Combined with the knowledge of how much has been spent, that should give us some idea of how long a complete transition would take, either at present levels of spending or at higher levels.

The situation is complicated by the fact that overall world energy usage is increasing all the time, so it's basically a case of shooting at a moving goal rather than a static one.  

If we compare the overall expenditure on renewables with the market penetration over the last decade or two, we can gain some insight into what kind of level of funding will achieve what rate of replacement of fossil fuels.

The above figures, from OurWorldinData, suggest that world renewables expenditure is around $250 billion per year. Some sources, eg the Guardian, put it at around $350 billion a year.  That's a lot of money.

A note here about numbers - I'm using the American definitions of billion as thousand million or 109 and trillion as million million or 1012. Since the words can have different meanings in different languages, and even different meanings in some English-speaking regions, perhaps we should avoid using them. Scientific notation as in 10n  is preferable since it has no ambiguity, but I'm writing this for non-scientists so that might not be understood.

Perhaps the most striking aspect is that most of the investment in the last two decades has been in wind and solar. Yet in spite of this huge cash injection, wind and solar don't even figure heavily in renewable energy stats, let alone in overall energy usage.

A notable feature is the surge in European expenditure around 2011, followed by a rapid decline until 2013, after which expenditure remained approximately level. Europe is the only region to have significantly reduced its expenditure, although others didn't see the rapid rise pre-2010. Overall, China has seen the greatest expansion in the renewables market. 

As we've seen most of this expenditure is on wind and solar, yet paradoxically most of the actual renewable energy consumed, comes from other sources. Here are the figures for 2016: 

We could be generous and say that wind and solar's contribution adds up to 1% of total energy usage. In reality it's more like 0.9% but like I say, we're trying to be ultra-fair here, to show the product in the best possible light. 

Note that we're talking about energy here. You may have seen figures for percentage of world electricity which look more favourable, possibly up to 8% by some sources. Electricity is, however, only a part of total energy usage. If the Greens have their way and force a switch to electricity for all heating and transport requirements, that will massively increase the world electricity demand. So in that case the figures for electricity and total energy will be much closer.  In any case it's the total energy from fossil sources which determines CO2 emissions, and that is the parameter we are told we must bring under control. Therefore I think we are justified in calling the electricity figure a red herring. Energy in total is what matters.


- Let's take a conservative figure of $200 billion USD a year over the last decade for wind and solar expenditure. 2009/2010 was after all the point at which this expenditure level was reached. The actual figure is higher, but again we're erring on the side of favourable reporting. Let's also assume that all current capacity was installed in the last decade. In fact most of it was, and ignoring the cost of capacity which already existed is again being as fair to the product as we reasonably can be -If we factored in all of the costs the picture would look somewhat worse.

OK, so that gives us an expenditure of $2 trillion over the decade, and it's achieved a market penetration of 1% of world energy.

If we were to continue at that rate, it would take 100x10 years or 1000 years to reach the magic 100% renewable energy, using primarily wind and solar. Assuming no change in the value of money (which is unlikely) over that time, the total cost would be 100 decades at $2 trillion a decade, or $200 trillion. 

For a start, we can see that a timescale of 1000 years is of absolutely no use to man nor beast. So, to have any meaningful impact on climate change we'd have to up the installation rate, and hence the expenditure, by quite a large amount.

Some climate experts have advised action in no more than 20 years, some say 50 is OK. Let's take a figure of 30 years, which gives us until about 2050 as I write.  To achieve this we'd need to up the expenditure to 200/30 or somewhat over six trillion a year.

Bear in mind this figure is just for the wind turbines, solar panels and cabling, etc to connect them to the Grid. It doesn't cover energy storage to cover cloudy or nil wind conditions, and that is likely to also be a very significant cost. It also leaves out any considerations of running out of suitable land for wind and solar farms before the objective is reached.


To put the figure of $6 trillion a year into perspective, it's more than twice the GDP of many first world countries such as the UK.


Often regarded as a modern wonder of the world, the Moon landings of the 1960's carry with them the air of a colossally expensive project. Yet, the Apollo moon landings project cost only a very reasonable $107 billion in modern money, to send 12 astronauts to walk on the Moon, and a further twelve to orbit it.

The '100% renewables by 2050 using wind and solar' project, at a cost of $200 trillion, is going to cost 1869 times as much as the entire Apollo Moon project.

Hinkley C

The insanely overpriced EDF Hinkley C nuclear station is projected to cost $38 billion over its constructional and operational life. So, the cost of the 100% wind/solar project is equivalent to over five thousand Hinkley C's. (Which, incidentally, is more than the total number of nuclear generating sites in the world today.)


The ITER fusion reactor project, arguably the world's most expensive and complex project of its kind, is slated to cost $15 billion or thereabouts. So, the cost of the 100% wind/solar project is equivalent to over thirteen thousand fusion reactors. (Only one needs to work... and all other renewables become museum pieces.)

Thorium LFTR

Thorium is a serious contender as a replacement for fossil fuels, and a full scale test would cost a few billion. Exactly how much is hard to quantify, some have said as little as $1 billion. Perhaps $5 billion would be a pessimistic figure, so let's take that as a worst case comparison. So, instead of going for the unattainable goal of 100% wind/solar energy we could build forty thousand experimental thorium reactors. Or more realistically, a handful of experimental units followed by a world rollout of the best-performing of these designs, at much lower cost than the wind/solar route.  For our 200 trillion we could expect to have something like 40 terawatts of generating capacity, running on low cost fuel. This is more than enough to  supply current world energy needs, and then some.

Conventional energy

A 1MW wind turbine costs about a million to build. A  CCGT gas turbine powerplant of 1GW output costs somewhat less than a billion to build. So at first sight the plant cost seems like it's about the same. However, the CCGT station runs 24/7  whereas the wind turbine operates at about the equivalent of 25% of the time. So in reality the plant cost for wind is at least four times that of natural gas.

If we take the projected $200 trillion cost of going 100% renewable and apply that to gas turbine electrical generation, for the same cost we could build more than two hundred thousand 1GW plants, or over 200 terawatts of capacity. A generating fleet of that size could produce the entire world's annual energy requirements (not just electricity, note) of 146,000 terawatt-hours in just 30 days of  of operation. Thus, the real difference in cost looks more like twelve times. That doesn't of course include fuel or operating costs, but it does give an idea of just how much more expensive wind and solar installations are, for the same notional capacity.

The cost in comparative terms

Since these huge numbers are often just that, and not something we can relate to everyday things, I've put together a few comparisons between the likely $200 trillion cost of going 100% wind/solar, and other large projects here.



BP Primary energy review 2018  (PDF)
BP full energy analysis 2018 (PDF)
-Note that renewables figures in the above two include all types except hydro, hence are not representative of wind/solar.