Renewable energy is reliable, new study claims


December 13, 2012

A new study claims that a municipal grid could be powered almost entirely via renewable sources (Image: Shutterstock)

A new study claims that a municipal grid could be powered almost entirely via renewable sources (Image: Shutterstock)

Although critics of renewable energy may claim that it isn't reliable enough to power a grid, a new study gives proponents of clean power – such as wind and solar – fresh ammunition to respond. A thorough analysis carried out by the University of Delaware and Delaware Technical Community College concluded that renewable energy could reliably power a large electrical grid 99.9 per cent of the time by 2030, at a cost that matches today’s electricity prices.

A diversified energy mix, an expanded geographic area of renewable generation, and efficient storage media such as batteries and fuel cells are key to running a successful renewable-powered grid. With that in mind, the study utilized a computer model that looked at 28 billion combinations of renewable energy sources and storage devices. It was found that a 72 GW electric system, for instance, could be run 99.9 percent of the time with a hydrogen storage system using 17 GW of solar, 68 GW of offshore wind, and 115 GW of inland wind.

Fossil fuel would be used in the event that renewable energy sources and stored power aren't able to meet demand. When supply outstripped demand, the model prioritized storing the excess power before using the remaining energy to replace natural gas for heating homes and businesses. If there was any excess left after that, only then it would go to waste.

The research spanned four years based on weather and energy demand data drawn from PJM Interconnection, a regional grid linking 13 states including New Jersey and Illinois. PJM makes up one-fifth of America’s total electrical grid.

In order to address the projected costs of clean energy, the study focused on minimizing costs instead of matching generation to electricity use, like similar studies have done. The authors used both current costs and 2030 costs, the latter of which they estimated would be about 50 percent lower than the former – they didn't assume new technologies would be developed, but did assume lower costs due to increasing production and technical experience. Maintenance costs were projected to remain the same.

The study also assumed costs without government subsidies, and compared them to the cost of generation of the most commonly-used types of fossil fuel, factoring in external costs such as the effects of power plant air pollution on human health.

The study makes a clear case for renewable energy (on which Germany is already sold) as a way to meet 80 to 90 per cent emission targets, which could be achieved if we aim for 90 percent or more renewable energy in 2030. Besides making environmental sense, it also makes economic sense, the authors say.

The research appeared online last month in the Journal of Power Sources.

Source: University of Delaware

About the Author
Antonio Pasolini Brazilian-Italian Antonio Pasolini graduated in journalism in Brazil before heading out to London for an MA in film and television studies. He fell in love with the city and spent 13 years there as a film reviewer before settling back in Brazil. Antonio's passion for green issues - and the outdoors - eventually got the best of him and since 2007 he's been writing about alternative energy, sustainability and new technology. All articles by Antonio Pasolini

Uhm, since 3 mile island makes 852 Megawatts, I'm not sure where the hell we are going to come up with the 17 GIGA watts of solar, 68 GIGA watts of offshore wind power, and the meager 115 gigawatts left over from off shore wind power...So i guess we simply need 219 times the power output of 3 mile island..Should be simple.


Lets do some simple math to check this "study" out ...

in 2009, average Gigawatts used per hour in the US 24/7/365 : 178

total capacity envisioned in the "study" : 199

but wait, by 2030 we will need at least 220 gigawatts per hour (assuming a 1% annual increase in electrical usage) ...

so assuming 100% electrical generation from the 3 sources 24/7/365 we would still come up short, 220 vs 199

of course the sun doesn't shine 24/7 and the wind doesn't blow 24/7

taking a generous assumption of 50% for wind and 35% for solar we come up with a capacity of 97 gigawatts ... again short of the 220 needed ...

the 16 gw of solar would cover an area at least 120,000 arces of land ... at a minimum ...

the wind component would need 122,000 of GE's 1.5 mw turbines ... (there are 16,000 currently installed worldwide) ... and would cover about 152,000 acres (much of that on land) ...

so in summary if we cover about 210,000 acres of land with solar panels and wind turbines and 56,000 acres of water offshore with turbines we can expect to generate about 43% of our electrical power in 2030 ... not 100% ...

nice try ...

Jeffrey Carlson

Jeffrey - I like the idea of trying, and since a heck of a lot of the base assumptions for the study are not mentioned in the article, of course one can easily come up with numbers that will destroy the case.

It's just like in 1900, when people with technical knowledge knew all the right reasons why motor cars could not and would not -ever- replace horse carriages. They did not tell lies, but yet they were completely, utterly wrong.

To see which way things are going one just has to watch any new technology.

Photovoltaic solar cells: "Experts" were at first (decades ago) telling people that efficiency could never go past 10%...20% and so on. Where are we now? At 43.5% for lab samples. I'm sure there are still, once again, people out there willing to tell me that I will never be able to buy a cell like that. You keep talking, while I keep watching price tags.

Computers: my dad was told he would never be able to afford a computer (just look how many transistors have to be assembled to make just one computer work!)

Wind: The first megawatt-class wind energy converter (the GROWIAN project) fell apart within weeks and, boy, were people bashed for that one. Waste of tax money! Impossible-to-overcome technological challenges, right? But it's 2012, power per unit is up to 7.5 Megawatts (not just 1.5 as you are using in your example) and still counting. 10MW units are being built, 15 MW talked about. Today, GROWIAN is known to have laid the foundation for modern wind energy with all that was learned from breaking that one windmill, back in 1983. And there are different technologies on the horizon now, kites, flying units with far more power and less materials going into than known today. Get ready to dismiss them all, you'll be busy.

Wave power: Have you looked at the power density of ocean waves? I'm sure your reply to that will be "but there is no one on earth able to harness that, at all" and I will tell you: "yet!" How many centuries did people tell other people that man and/or machines can't fly?

Batteries: Don't even get me started on that. I so well remember expert statements from as little as 15 years ago, when polymer-based rechargeable batteries only existed as badly functioning lab samples, and look where we are at now.

Flat computer screens. .. I remember so many experts telling me why "never there will be color screens", or why it will "never be possible to make screens larger than ...x... diameter". Or, flat screen TV's! Geez, what a pile of bull.

Houses are already being built that only use a tiny fraction of the energy of todays houses for heating. Ever heard of the "Passive House"? That type of house is so well insulated, cozy temperatures are maintained from the heat of the bodys of the inhabitants. The first set of row houses of that type was built in the 90's, in Darmstadt, Germany.

The Tesla S electric car was not possible a decade ago. Yes, yes, you don't have to tell me the price tag. Just wait, dude. The Toyota Corolla did not happen overnight, suddenly, in 1901. Things take time.

Technology is advancing. Costs for renewables are dropping. Fossils are running out, and who cares when exactly that happens? It will happen.


I'm sure there will be technological advances in clean energy by the time 2030 comes around. So you really shouldn't base your argument on current technologies.

Brian Maxwell

Jeffrey, while it is correct that there would be considerable land usage involved in the generated energy I think you've skipped a couple of features of the study: 1. "...could be achieved if we aim for 90 percent or more..." The study wasn't about supplying 100% of power. 2. Does the projected power output of the renewable sources used in the study mean total maximum theoretical or does it mean realistic practical? Eg: 199GW from renewable sources would have to be factored down if that was a max theoretical figure. But if the 199 has already taken into account average sunny days and windy days then you don't. There is as you point out, the issue of the land area consumed by power generation. But only if you assume a centralised energy distribution system. If you stick a few KW of solar panels on everyone's roof you can spread the load and land use out over already used land. In Australia, particularly Western Australia, 1.5kw of grid connected solar panels cost as little as $1,500 - $1,800 installed and 3kw just under double that. Around Perth (where pretty much everyone in WA lives) we get 5.5 sun hours / day on average so with the 3kw package each house would make 16.5kw/hr /day. You wouldn't need to use up perfectly good land for solar, just put more panels on roofs. Wind of course is different due to visibility and noise issues. "Aim for the stars and you might reach the moon"


I just hate seeing all those windmills and solar panels on the horizon... Not to mention electricly connecting all those "renewables". Germans love windmills only when they are not in their back yard.

Travis Tarr

I suspect that at the very best a detailed inspection of the study will find that the cost estimates for the renewable energy sources are uniformly highly optimistic while the cost estimates for all the conventional energy sources are uniformly highly pessimistic.


while it is good to research the possibilities making such wild claims will only continue to polarise opinion.

To suggest technologies can be developed, be taken out of the lab and form part of the day to day operation of our critical infrastructure that we rely on in 13 years is crazy.

I personally have problems with the way wind is being promoted in the UK and the green credentials it has been given. If you look at the wind production figures in the UK in last week you will see for the last 3 days production has been at less than 25% of the typical peak, to provide systems capable of storing this much power to make up shortfalls over a period of up to a week using technology by committing to technology that is not proven would e reckless. It should be noted that Wind turbines in the UK typically provide 20% of their design maximum on average.

While solar is more predictable the stochastic nature of wind production cause huge problems for electrical grids. Denmark produce in excess of 20% of their electrical power by wind but you should read this report to see the issues it causes them and what it would mean if it was applied to the UK or USA.

By all means look to the future but lets not make snap decisions on such an important issue using sound bites.

Nigel Giddings

Hi all,

Since we are talking numbers, I thought I would add by US$0.02 worth.

9,827,000 km² United States of America, Area ( found it on Google )

Total area needed as estimated by Mr Carlson : 210,000 + 56,000 acres = 266,000acres = 1,076.4638 km2 (round up 1,077km2) = 415.62 sq miles

As a percentage : 1077 / 9,827,000 x 100 = 0.011% (approx.) of total land area of the US of A Or 32.82 km by 32.82 km area = 20.39 miles by 20.39 miles

I've never been to the States but I think you can spare the space for this

Oh! and if thats a problem there's still the Aussie example... Aussie Aussie Aussie!! Ooi Ooi Ooi!! Roof tops are great! And Perth is beautiful, Peppermint Grove is lovely, great picnic spots..


well, I rather trust in a study, than in a bunch of nonsense opinions. And as usual I read a heap of a loosely based on numbers presumptions of a nuclear lobby. Please keep calm and carry on investing in renewable energy, and not in finite combustion materials & pollution.

Stefaan van Damme

Naysayers are an amazing, and powerful lot. Just look at how long they kept the world flat! (yes, I am laughing) It'll never work! We're doomed, I'm just sure we are! The sky will surely fall if we try to use alternative fuels sources instead of fossil fuels. The well will never run dry. That can't work. It's just a fools game to ever try anything except the tried, and true... Bah!

The proverbial David Neal


First you have 'believe' in man-made global warming, which is nothing more than a prediction based on faulty and fabricated data.

Then you have to believe that wind and solar power will eventually work efficiently enough to displace other proven technology such as nuclear, hydro power, and nat gas power plants.

It's like all other religions - you believe because you want to believe. Evidence and proof don't matter.


Electric companies will make this happen. Why? Economics. No one wants to trust either the availability or price of fossil fuel.

Truth be known, solar panels work quite well in cool/cold sunny climates; probably better than in warm sunny climates (heat loss, component longevity). They are getting better but, even if that were not true, they are becoming quite in expensive. Architects and retro-fitters are adding them to both commercial and residential construction with increasing frequency. They can be placed just about anywhere and produce zero noise - great for local power production.

In the same way computers and the internet democratized information and knowledge, Solar Power allows both developed and developing nations to address their concerns: one wants less pollution and cost and the other wants to bring economical low-maintenance power to all of its communities which, if they do have power now, have to rely on expensive full-sulfur diesel.

We can thank the Chinese for dropping the price of solar by producing large quantities of cheap solar cells/panels. This may be their shining achievement in solving what has become an acute OPEC problem.

Combine solar, geothermal (two types) and wind and you have a very viable set of solutions. Natural gas will still be needed but only to charge batteries or act as backup.


I appreciate the optimism of the authors, but the claims being made go well beyond the facts.

Until someone develops a way to store energy (battery, super-capacitor, other), wind and solar are viable as supplemental methods of power generation only.

Power plants (powered by fossil fuels or nuclear fission) must be online in order to cover the night hours and cloudy days when the sun isn't shining and also the calm days when the wind isn't blowing.

Please omit the political spin and just give us the facts!


If the study us accurate, then they should go ahead and try it in a mid sized city/state or nation I know Germany is trying and I wish them luck. Of course if they are wrong they are going to hurt their economy greatly....Like Spain has.

Tacit , implied, understanding: The Cheap Oil Era, American Golden Age, American Dream lifestyle, will be morphed into oblivion by new world wide economic situations, scientific discoveries, technological realities in Asia, leaving a static American population surviving well, but on much much less, through technology. Wireless communication over Telegraph wires, local Solar, Wind and Thorium generated electricity, without huge transmission losses, expenses. Electric bullet trains, passenger ans freight fully computer controlled replacing the whole of the American Jet flight syndrome, the American Auto romance. only small 'short hop' domestic electric powered ballast battery cars allowed by prohibitive gasoline taxation, costs. Super insulated, survival sized, not ego sized housing with guaranteed payable mortgages and guaranteed longevity. Very few Uber Rich and a much better distribution of wealth in the U.S. Currently: "One of the most significant events in this recasting was the realization in the early 1980s that the average American consumed as many natural resources as 1000 average inhabitants of India. It was also realized that the average American produced as much waste (including the all important carbon footprint) as 2500 Indians! even today, the ratios are still approximately 1:300 (US compared to India) and 1:500 compared to China." These numbers will be changed by the new Asian economic reality in the world. China has already "exploded" the "Population Bomb" , initiated mass produced Thorium LFTR styled reactors, that will "Alter the Global Energy Map Forever" America still faces horrendous debt obligations to China, Japan. Be advised: India's population with IQ's over 130, is higher than the entire U.S. population! more English speaking Chinese on the internet than English speaking Americans today! India buys mig 50's over U.S. F-35's cite better technologies, cheaper, more dependable, more effective planes, Norway has a thorium LFTR styled reactor underway, cite cheaper to build, cheaper local fuel supplies over American designs. World drives Asian cars with Chinese parts, even whole sub-assemblies now, even domestic 'American" cars rife with parts, sub assemblies and whole engines in some cases from Asia, not America?

Bruce Miller

1) and don't count out conservation - changes in efficiencies, consumer choices, could have an impact if people constantly aren't told that it's "impossible". Impossible things cost a lot now, but as noted above, they often are not only not impossible, but probable.

2) again, as stated in other words above, diversification is huge. Have we learned that lesson yet? Solar, wind, geothermal all can generate on-site and can and should be integrated into populated areas. Distribute the production, reduce some of the necessity for transmission, network the production sites via the grid (smart, dumb or indifferent).

3) even 5% efficient solar generation, if made cheaply available, could be adopted by many, and any who were interested. Any alternate generation is a start. A perfect solution doesn't have to exist to get started (a lesson I often forget). The perfect tech will never come along. Use what we have!

Also as stated above, a bunch of blather in the form of comments and criticisms, whatever the potential value of it, is just blather unless it becomes part of a larger discussion.


Hydro power is the only form of renewable energy that is reasonable to build or use. Hydro power is considered a nonrenewable by most governmental organizations.

David Cordon

Sorry to burst all of your bubbles But Solar nor Wind will ever replace base load electric generation...until we alienate the need for base load generation ...PERIOD...and it is real simple to do and we can as a country do it by 2030...instead if Stupid Grid Generating Hugh amounts of electricity 200miles away from End User.... Retro fit all users with there own needs @ point of use... Also the newest R&D in Wind generation is not that giant 1.5M turbine that is noisy as hell and takes a 20knot wind just to get it spinning... It is Magnetic Levitation Vertical Axis wind friction , no bearings to wear out and you can virtually blow on it and it spins very low wind speed needed...

But the only large generation that can even truly compete and we can build starting tomorrow is Hybrids on Landfill application were you have Solar on south slope , Mag Lev Vert Wind on top of peak, Methane burners every were on mound and Waste to Energy Plasma Gasification and heat recovery killing 2 birds with one stone... and you can do this easily @ the 100Meggawatt level...

But again it is local co-generation that will get us to the right levels in the next 20yrs...

Mini generation every were, and of course there is that other matter so if natural disaster comes thru and blows out one station entire grid does not shut down every one else does not go with out for weeks at the time...



Well this article certainly makes me feel better while I wait for my 2kVA inverter to be replaced under warranty for the second time because it was (is??) hopelessly unreliable.

Also, I grew up in Peppermint Grove and I challenge Hamstermeister to find a single solar panel or wind turbine in the whole shire. Even the yachts at RFBYC spend most of their time under bare poles with the diesel doing the propulsion.


People hear geothermal and think of a geyser like Old Faithful or boiling water pools in the wilderness and parks. when it is simply the average of 50 degrees and above temperature of the earth every where on the planet below the permafrost layer this is concentrated with a simple system to heat any home create hot water for all needs while powering a Sterling external heat engine to generate electricity to power the home day and night with grid ties to shunt off excess energy to the grid day and night.

Those who want to cram into tiny boxes and self neuter to save the planet from over population more power to you! The moment you try to force me to do the same will engender your desired self demise saving the planet further.

Joseph Mertens

Renewable energy is the way.


The study also assumed costs without government subsidies, and compared them to the cost of generation of the most commonly-used types of fossil fuel, factoring in external costs such as the effects of power plant air pollution on human health.

Some how I suspect this includes a Carbon tax.


Hi nutcase,

Thanks for bringing up the inverter "fritzing" out. Regret to hear about your predicament. I am extremely interested in the brand (we can take this off line ) because I was recently approached by a supplier from a certain asian country claiming fantastic results and sale of inverters between 1-2kW... His main market? Australia..

We've installed German inverters in all our previous installations, and they are humming along nicely.

Also I will be happy to put you through to a friend over at NSW who was previously asked to check on installations particularly, on quality and performance issues

As for peppermint grove... Didn't say I saw PV installed, I liked the picnic spots there = )


There is already an effective way to store excess energy from solar and wind: Hydropower. It is used to pump water up the dam, so then at a time where it is needed, can be used again generate power. The problem is that not every country has an opportunity to build a hydro dam, but its neighbour might have one, so one can sell excess power to them.

Fretting Freddy the Ferret pressing the Fret

I notice that the extra BILLION energy consumers every ten years or so is not factored in. What am I on about? The earth's population is projected to increase at the above rate. They all deserve a reverse-cycle air conditioner, just like the one on your wall. Faced with this you have to admit sustainability is a sick joke.


consider that the alternative is to keep on using oil, coal, gas, and that these power sources are going to keep getting more expensive over time, like in about 20 years they won't be viable any more. At that point, I think windmills will look pretty nice on the horizon.

but, ahem, on the sustainability front, I'm hoping we can still have bicycles and roads.

David Lewis

Fretting Freddy the Ferret pressing the Fret, in many cases, dams cause more problems than they solve. they destroy species that must move up and down a river to spawn. Many small dams have been bought out by conservation groups and the dams have been removed.

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