In a recent post, I discussed why the US needs, on average, 15,000 additional megawatts (“MW”) of new power plant capacity – each year! – just to keep up with the growth in domestic demand for electricity. How many new power plants have to be built to accommodate this national thirst for energy?   Two power plants a year? Five? Ten?  And what  if all of that new power had to come from renewable energy – say solar – as so many in the green community suggest it should, or more urgently, demand it must!? Is it even technically feasible to satisfy our annual electrical demand growth from solar alone?

Of course, the number of new plants (or generating units) needed to supply 15,000 MW of new capacity each year depends on your technology of choice.

• 15 – Large scale 1,000 MW coal fired or nuclear power plants
• 30 – Medium sized 500 MW natural gas, coal fired or nuclear power plants
• 7,500 – Utility scale 2 MW wind turbines
• 75 million – 200 Watt solar panels.

In reality, 75 million solar panels a year isn’t enough. It’s too low because solar panel manufacturers rate their panels DC whereas our electrical grid uses AC power. Using an approximate conversion factor of 0.85, the real number would closer to 88  million – each year. Are we done? Install 88 million solar panels each year instead of 15 large coal or nuclear plants? Hardly.

There’s the pesky matter of cloudy days when a solar plant can’t produce at full power. That’s the rub with most renewable power including both solar and wind. It’s intermittent and you can’t count on all of it being there when you need it.  On average, a typical solar power plant might have a capacity factor rating of roughly 20%; even lower in locations with less abundant sunlight.  Said differently, you could build a 100 megawatt (“MW”) AC solar facility but on average you could only count on 20 MW (20%) being available on any given day. But there’s a niggling problem with that that word “average”. On a bright, clear sunny summer day that solar plant might  produce 100 MW (100%) power during midday. But on a cloudy day in winter it might only produce 5-10% of peak output. In fact, it might rarely ever produce at exactly the 20 MW average. And then there’s mornings and early evenings when the sun is waxing and waning and only a fraction of the 100 MW nameplate rating is produced. Finally there’s that inconvenient daily event…..called night….when the output of  a solar plant is nil, nada, zip – all night long.

Follow this to its logical conclusion and you might want to have some backup power plants that can fill in for the solar plants when the sun doesn’t shine (or shines less than needed for solar output to meet the electrical demand).  And these backup plants had better be ready when you need them – the very definition of “firm capacity”. Today, firm capacity comes from fossil (mostly natural gas and coal) and nuclear plants. By now you might also be tumbling to the fact that 100% of our electrical needs cannot be met with intermittent renewable energy like solar and wind. Simply stated, until we figure out how to store massive quantities of electrical power economically, we need the kind of firm capacity that can only come from fossil and nuclear power plants.

Please don’t misunderstand me. I’m a big fan of renewable power and solar in particular. I think solar has… (forgive me) a sunny future! However, green energy proponents who oppose all forms of fossil power may be the greenest of green advocates but all too often appear willfully ignorant of the realities of delivering reliable electricity 24×7 to consumers.

Today, regulated utilities, independent power producers, regulatory authorities, politicians and rate payer advocates are all engaged in a healthy debate over what percentage of renewable power is practicable.   There is broad consensus that at least 25% of the our electrical power demand can be met with renewable sources. The “25 by ’25″ resolution recently passed by the House Representatives expresses the sense of the Congress that by the year 2025, at least 25 percent of total U.S. energy will come from renewable, domestically produced sources. Since we’re at approximately 9.5% today (source EIA), if enacted into law, we would need an incremental 15.5% over 16 years.

Let’s assume for a moment that all of this incremental renewable energy were to come from solar (admittedly unrealistic but bear with me here). The US currently produces/consumes approximately 4.1 billion megawatt-hours of electricity annually. 15.5% of this is about 615 million megawatt-hours. Assuming 99% reliability and a 20% solar fleet capacity factor, this would translate into 431,050 megawatts DC of newly installed solar panels. Assuming 200 watt DC panels, we’d need approximately 2.2 billion new panels to hit the 25 by 25 target.  If we built one large 431,050 megawatt DC solar power farm, we would need 3,368 square miles of land (assuming 10 acres per megawatt). To put this into perspective, that’s a square parcel of land 58 miles by 58 miles or approximately 0.1% of the total US land area excluding water bodies. You could circumnavigate this solar plant in roughly 4 hours driving at 60 mph. Imagine this facility being located in the hinterlands of the greater southwestern US. Not too hard to imagine, no?

Ok, so we meet our national mandate of 25 by 25 with a 60 mile square swath of solar panels (of course in reality never all at one location and not with 100% solar). I don’t know about you, but I still want electricity at night and on cloudy or rainy days. So lets talk about backup power for the 25% of energy coming from solar. Backup power would only need to operate at night and partially on some, but not all, days during daylight. This intermediate load resource would have to be the lowest cost to build while also not costing too much to operate. Nukes are VERY expensive to build, difficult to finance,  although cheap to run – not the best fit for  backup. Coal plants are relatively less costly than nukes but more costly to run (and getting costlier if you assume carbon taxes or carbon capture/sequestration) plus they have an enormous carbon footprint that threatens their viability. Just try to permit one today. Good luck. That leaves simple and combined cycle gas turbines burning  natural gas. Least cost to build, much lower carbon footprint than coal, financeable, easily permitted and reasonable cost to operate provided natural gas supplies remain abundant and reasonably priced. The good news is that the long-term natural gas supply picture has improved greatly over the past 2 years and prices have come down accordingly.

So there you have it. Solar, wind and other renewables generating at least 25% of our energy backed up mostly by natural gas and maybe a few more nukes. As coal plants retire, a mix of new renewables and gas fired plants will take their place. The renewables mandate may even increase towards 50% or higher over time. A diversified mix of solar, wind, geothermal, and biomass may even require less backup power than initially thought especially if the electrical grid is expanded. Should large scale power storage becomes feasible, the days of fossil fired power may eventually fade.  Until then, fossil based power generation is going to be part of the mix. Welcome to the future of our electrical supply – real or imagined?

Given the volumes of print, video and chatter on  climate change, the evils of coal (including those mythical  “clean coal” types) and the panacea that is renewable energy, the average person could be forgiven for wondering why on earth the people who are in the business of producing and selling electricity aren’t running – instead of crawling or being dragged – towards something as reliable, clean and universal as solar power.  Notwithstanding some movement towards solar in states like California and to a far lesser extent New Jersey and Connecticut (the majority of which is small distributed roof-top projects), the vast majority of U.S. utilities have barely budged towards adopting solar in any meaningful way. Not that they aren’t aware of solar or aren’t sudying it mind you. They just aren’t buying into big megawatts of it. Why is that?

If you’re a rabid environmentalist the usual suspects are “big oil” and similar dark industries with sinister motives that are effectively blocking renewables while the earth withers.  If you’re a coal miner, you’re hoping like hell that those same suspects are effectively blocking those tree-hugging renewables and protecting us from destroying our domestic economy and electricity supply system as they tear the top off another Appalachian mountain for another layer of coal.  At least this is the general impression you get from reading most blogs and the conventional news media.  So of course it must be true.

Or maybe not.  Our friends at the Solar Energy Power Association (SEPA) decided to take a more direct approach and simply asked the utilities about their views on buying solar power.  SEPA just released the results of its Utility Procurement Study entitled ”Solar Electricity in the Utility Market”.  Not exactly light casual reading, this 117 page report gets high marks for being candid, clearly written, and a surprisingly comprehensive overview of how power, especially renewables, have been purchased by utilities over the years. And then of course there are the conclusions.

1. Solar is just too damn expensive and so far utilities can get all the power their customers  need from lower cost sources
2. When utilities do buy solar, they buy it because they’re made to do so by state laws and regulations that say buy it anyway, price notwithstanding (thus their collective asses are covered by regulatory mandate as they pass on these politically acceptable higher costs to their rate payers)
3. But utilities really do like the non-price features of clean,  no emissions, no-carbon solar energy ……really, they do….a lot….it’s on the top of their like list
4. The solar developers need to suck it up and stop bitching about the tough terms and conditions of the power purchase contracts
5. The solar developers need to learn how to make firm price bids and then stick with ‘em – just like all the other developers – sure, all you solar guys are special but you aren’t that special
6. The utilities need to chill some and start offering kinder, gentler long term power purchase agreements that weren’t written by lawyers from hell (hope springs eternal!)
7. Utilities need to take some 400 level courses on solar and the solar developers need to supply the instructors and coursework
8. Utilities just aren’t very impressed with the on-peak aspect of solar and wish the developers would stop harping about it – and developers have a hard time believing this for good reason
9. The cost of solar energy needs to come down and when it comes down far enough the utilities will run….not walk….towards solar. Depending on who you talk to this is 2-5 years away from a tipping point.

So there you have it. Mostly solar costs too much. The report goes into much more detail of course but it more or less makes many variations on the above points albeit with dryer language.

Notice the absence of big oil or other dark sinister actors? Unless you consider the uitlity business to be inherently dark and sinister. But really, utilities just want to keep the lights on, the politicians happy, and the regulators off their backs while they earn a 10-15% return on invested capital. Is that asking too much?

Bottom line on solar energy and most other forms of more expensive renewable energy is this:  If we’d all agree to accept paying twice as much for our electricity then we do now, then solar, and renewable energy generally,  would explode and over the next 10-20 years coal would slowly recede. Who’s ready to sign up for doubling their power bills?  Don’t all raise your hands at once.

Alternatively, the feds could lead with a nationally mandated renewable energy portfolio standard with painful consequences for non-compliance by the load serving utilities. See item #2 above for clarification. Either way we would end up paying much much more for the cleaner energy we need – say maybe twice a much.

It’s really not much more complicated than that.  Call or write your state utility commissioners and state representative and tell them that it’s ok to double your electrical bill if that’s what it takes. And you won’t bitch or hold it against them during the next election. Promise!