Is renewable energy ready for the real deal? How do we match supply and demand? We all know about the intermittent character of wind, water and solar. The sun does not shine all the time; the wind doesn’t always blow. Here is a study from Stanford University that is looking to answer how a key, energy intensive region of the country, New York state could be run entirely on renewable energy. Can it be done? Yes.
The study can be looked up here. It is technical yes, but the answer is simple: it can be done quickly and affordably. A similar study has been done by the University of Delaware that includes a much more detailed and specific look at how a shift to renewables could replace, watt for watt, the current system in a large regional grid called the PJM Interconnection, representing 13 states and one fifth of the US grid. I tried to summarize a few key points from the New York State study with help from Peter Sinclair.
1. What are the main ingredients of a fully renewable energy economy?
The graph below shows you the current situation and how the pathways transition into the new energy future. You see some key ingredients. The biggest step is the missing loss of energy when we do not rely anymore on fossil fuels that we have to convert to electricity. That is a good bonus to have! The next path is being more efficient with the energy we use. Doing more with less. Wasting less by being smarter. You know, stuff you can do yourself, like changing a light bulb to a CFL. When you look at the black section, you almost see a perfect bell-that is about half of the trick, almost. The energy that we still need will be generated with an intricate mix of energy sources. It is all of them: solar, wind, hydro and geothermal. And yes, we need them all so they can dance and make it all work together.
2. So we are talking about all energy uses?
Yes, we can not just talk about electricity. It is about an all-purpose energy infrastructure for electricity, transportation, heating/cooling and industry. It needs to be a comprehensive energy strategy and it should focus on all the services we derive from the use of energy. So we are indeed talking about the full replacement of the use of coal, natural gas, nuclear, shale gas, tar sand and oil.
3. Can you show me what sources of renewable energy are part of the mix?
It is a colorful palet of energy sources which will vary wherever you are in the world. If we look at New York State (NYS’s) 2030 all-purpose end-use power would be provided by:
10% onshore wind (4020 5-MW turbines),
40% offshore wind (12,700 5-MW turbines),
10% concentrated solar (387 100-MW plants),
10% solar-PV plants (828 50-MW plants),
6% residential rooftop PV (~5 million 5-kW systems),
12% commercial/government rooftop PV (~500,000 100-kW systems),
5% geothermal (36 100-MW plants), 0.5% wave (1910 0.75-MW devices),
1% tidal (2600 1-MW turbines),
and 5.5% hydroelectric (6.6 1300-MW plants, - of which 89% exist).
Yes, your solar panels on your roof are part of this success as well! And all of this is existing technology.
4. And it pays for itself in dollars and even more in health and jobs
The conversion would reduce NYS’s end-use power demand ~37% and stabilize energy prices since fuel costs would be zero. It would create more jobs than lost because nearly all NYS energy would now be produced in- state. NYS air pollution mortality and its costs would decline by ~4000 (1200-7600) deaths/yr, and $33 (10-76) billion/yr (3% of 2010 NYS GDP), respectively, alone repaying the 271 GW installed power needed within ~17 y, before accounting for electricity sales. NYS’s own emission decreases would reduce 2050 U.S. climate costs by ~$3.2 billion/yr.
5. But, do we have space for all of this?
The answer is simple again: yes. If you look at the map below where the technologies from question 3 are plotted, you see that it would require space, but that there is plenty space left for biking, hiking and other outdoor activities that will let you breath in all the clean air.
6. And, how are we going to deal with challenge of matching the demand, at different times of the day, and the activities of nature?
An important concern that needs to be addressed in a clean-energy economy is whether electric power demand can be met with wind, water, and solar supply on a minute, daily, and seasonal basis. There are a nice array of methods that we can deploy to do just that:
(A) combining geographically-dispersed renewable resources as a bundled set of resources rather than separate resources and using hydroelectric or stored concentrated solar power to balance the remaining load;
(B) using demand-response management to shift times of demand to better match the availability of renewable power;
(C) over-sizing renewable peak generation capacity to minimize the times when available renewable power is less than demand and provide power to produce heat for air and water and hydrogen for transportation and heat when renewable power exceeds demand;
(D) integrating weather forecasts into system operation;
(E) storing energy in batteries or other storage media at the site of generation or use; and
(F) storing energy in electric-vehicle batteries for later extraction (vehicle-to-grid).
My conclusion is that if we focus our effort on getting this done, we can. We need to do two things: start investing in the conversion and stop investing in fossil fuel based infrastructure.
If you look at all the challenges facing food producers around the world, you could argue that the most daunting one is climate change. Higher temperatures, higher sea levels, crazy weather… Well, it turns out our food system isn’t just challenged by climate change — it’s also one of the biggest sources of greenhouse gas. Most of it comes from the production end — methane from cattle, nitrous oxide from fertilizer, CO2 from cutting down trees — but several recent studies have concluded that we will never be truly food-secure unless we change the way we eat. 
Despite climate and energy policy inching forward in Congress and at the UN climate change negotiations in Qatar, a new report from Calvert Investments, Ceres and World Wildlife Fund (WWF) shows that most of the world’s largest companies aren’t waiting on governments to embrace renewable energy and lower emissions.
You can check out website of Westmil solar co-op 
