I Want to be Independent of the Power Grid
How Can I Do That?
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Today, I will talk about:
Microgrids
Smart meters
Virtual power plants
So, How Do I Make This Happen?
This is living the green new dream, right?
Put solar panels on your roof - ideally integrated into your roof tiles. Install battery storage.
Install enough panels and batteries to power the whole house at any time of year, no matter the weather. Say goodbye to your utility, and don’t worry about power outages.
Let’s start by looking at your utility bill. Oh, wait. Do you get your gas from your utility, too?
So, maybe you can’t go completely off the grid. Well, let’s come back to that.
Here are the steps:
Look at your utility bill to determine your monthly usage and divide it by 30 to get your daily usage. Ideally, you want daily usage because you want to know real-time peaks and troughs.
Now, you need to get some specifications for solar panels. The output per panel is 400W (typical for residential installations), and you need 70kwh daily.
Assume the panels generate at 80% efficiency. You will need a total generation of 87.5kWh (70/0.8).
Assume the panels produce for 5 hours per day. That means 400W*5 =2,000W =2 kWh.
That means you will need 87.5kWh/2kWh panels = 43.75 panels for a total system size of 17.6kW.
A system of that size would cost, on average, around $47,250 after applying the $20,250 solar credit.
Of course, since we are going off-grid, we will need to consider storage for the other hours of the day when the panels are not producing power.
Based on my home, I estimate that during the peak summer period, I use 50% of my electricity between 6 PM and midnight and another 26% overnight.
That means I need to be able to store around 75% of my total power needs in a battery that can discharge until the sun shines again.
If I need to cover 75% of my daily load, 70*75% = 52.5 kWh.
For battery health, I need to assume only 80% discharge, so I will need battery storage of 52.5/0.8 = 65.625 kWh.
The average Tesla Powerwall is 13.5 kWh, so I need around 5.
Each Powerwall costs around $8,400 before the 30% tax credit. The total will be $42,000, or $29,400, after the 30% tax credit.
Also, my peak usage is 130kWh, so I must overbuild my system to ensure I can handle those peaks.
Going back to the gas, I must replace that by installing a heat pump, which will run off electricity.
The average cost of a heat pump is around $6,000. Of course, it depends on your house's location, climate, and size. You may also need to upgrade your electric panel (because your EV will pull a significant chunk of power), and installation can cost $4,000 to $8,000.
At 16 bullet points, we have only begun to scope out the work needed to complete this.
The vendors supplying the panels, batteries, heat pump, installation, and consultation will be pleased to work with you.
They may also be able to lease some of the equipment to you if you don’t pay enough taxes to take advantage of all the tax credits.
The utility may have questions, especially if you need to upgrade your service. None of this will be straightforward, and you may need to offset the benefits of grid independence against the cost and calculate the payback of the expense compared with the cost of simply continuing to pay your utility bill.
Microgrids can operate independently from the grid and can be an intelligent solution for isolated homes or specific communities. They are challenging to implement for individual homeowners who are otherwise well-integrated into a utility district.
So, let’s look at something more realistic.
Let’s Make A Virtual Power Plant Instead
What’s a virtual power plant?
I have mentioned before that some essential reading is necessary to understand how the electric grid works: Shorting the Grid by Meredith Angwin, and The Grid by Gretchen Bakke.
The first discusses the two aspects of the physical grid—power plants and transmission lines—and the policy grid, regulations, and market structures.
The second traces the evolution of the grid and its regulatory context, starting with President Carter and the vital legislative initiatives he started.
Bakke discusses how the grid works and suggests that it may need to evolve from its current form to address some of its challenges.
One possible future is the mass rollout of virtual power plants (VPPs).
VPPs rely on a network of decentralized medium-scale power generating units, flexible power consumers, and storage systems.
VPPs can help deal with the problems of intermittency and the challenges posed by the multiple power generation sources—wind, solar, combined heat and power, nuclear, and electric vehicles—and make them all work as one team.
The key to this vision is smart meters.
A Nest thermostat is not a smart meter. A smart thermostat allows you to control your home's heating and cooling.
With a Nest, you can control your home remotely to ensure the heating or cooling is set to your required temperature when you return home from vacation.
Just as the Nest gives you insights and control over your home, a smart meter gives your utility insights and—if you allow it—control over your electricity consumption.
I can open my Coned bill and see how each appliance draws power. So can Coned.
Many people resent giving up this information and control to their utility, fearing they will have their heating or cooling curtailed just when they need it most.
The reality is that the utility wants to do that only to prevent widespread emergencies or shortages.
If you allow it, the utility may be able to make your home a little hotter or cooler on the relatively few occasions when the grid is stressed. Would you allow that? I think I might.
Teamwork Makes The Dream Work
VPPs are a sophisticated solution to a complex problem. There are many advantages to renewable energy generation.
The resource is widely believed to be free: the sun rises and sets daily, and the wind blows.
However, the wind doesn’t always blow predictably and can be fickle when needed most. The sun is predictably absent at some times of the year and in some places more than others.
The backup required to supplement these resources is costly, which can sometimes raise the question of whether it is worth using resources that need backing up.
However, just as it is pointless to ‘fight the Fed’ in trying to trade the financial markets, the wave of renewable energy resources is getting stronger. We need to figure it out.
VPPs are a way to smooth the integration of intermittent resources into the grid. When the wind dies and the sun goes down, a VPP can access other available generation or storage resources to blend them inefficiently and seamlessly.
Combined-cycle power plants - the most frequent backups for solar and wind - take a few minutes to ramp up. While doing so, a VPP can add battery storage to provide short-term power like a conductor in a symphony.
If the grid was stressed, a VPP could signal to a factory operator or the operator of an industrial plant producing heat capable of being used for power to detach from grid power for some time and use their own resources.
A VPP could tap into the many EVs plugged into the grid at that moment and discharge a portion of their batteries to supplement a power surge. EV owners would need to consent to this. The more that do so, the less intrusive the operation would be for each owner.
Utilities are happy to pay EV owners to charge their vehicles overnight at off-peak times precisely because this helps them manage their demand.
Takeaways
Living off the grid is expensive and, for most people, not worth the hassle.
Microgrids can make sense for specific communities but need to be implemented on a multi-home basis.
The electric grid in the United States is stressed and needs attention and investment.
We will unlikely soon find the political will to implement large-scale regulatory reform of our energy system.
VPPs are an intelligent solution to a complex problem and can be crucial in integrating multiple energy and storage resources, making them complementary instead of competing.