(Continued from Part 2. This concludes the article.)
6th Backup Option: A Permanent Mid-Size Solar System
This system is advertised as an auto-transfer battery/inverter system that is designed for modular build, which provides the ability to add additional batteries and inverters as your system needs grow. It is a way to start with a solar backup and grow to a full power system in the future.
[JWR Adds: If you plan to eventually expand your system then choose modular, expandable components. For example, select modular stacking inverters.]
As with most systems, these systems are basically composed of a power generation method, a storage capability, an inverter that takes the energy from the storage and makes it available for use, a means to charge the energy storage system, and a variety of wiring systems and accessories that tie it into the user’s system. Usually it is a modular system that uses one or more battery modules, one or two inverter modules and multiple solar panels. Proper initial layout will allow the addition of modules in the future.
The batteries are typically charged from the grid and/or solar panels. The size and number of batteries and solar panels is determined by your needs analysis.
Many of the companies that sell portable solar generators also sell larger units.
Notice that this system is similar to the fifth option but based on battery DC power storage instead of engine technology.
Advantages include the large size of the available power backup for system solutions, the use of solar panels, quiet operation, interior and exterior mounting, and modular construction for lower initial cost and future expansion. Note that a system may be eligible for power co-op incentives, as well as state and federal incentives. They often have a phone app for system monitoring and control.
Disadvantages include: The mid-range cost. The modular construction may also result in a more complicated system. You will need to find a reputable, honest, and properly-licensed contractor to ensure that it meets your needs and is properly installed and supported. Even if you can do the install work, you need to have it inspected to ensure proper operation. You may need permits from your community. You should ask about EMP susceptibility if that is a concern. Recent revelations of hidden communications and possible control capability in Chinese-sourced solar components make it important to have communications with an anti-hacker protocol built in.
7th Backup Option: A Permanent Large-Scale Solar System
Systems that are sized, designed, and installed for whole-house support are becoming more common. Basically, they are scaled-up versions of the smaller systems that I have discussed. However, the design as a large, whole house-system allows economies of scale, layout, and design.
Electrical company tie-in: There are often electrical utility programs that install solar panels on a home and pay the homeowner for the electricity generated. Unfortunately, many of these utility company-based systems do not have a storage method or way to use the power generated when the grid is down.
However, you have the ability to procure a properly-designed system that will include power generation, storage, conversion from storage to system needs, and often a means to sell excess power to the grid.
A concern with some “sell-back” or net-metering systems is the lack of local power storage at your location. Some plans only sell power to the electrical grid, and if it is down, then power is not available to you.
[JWR Adds: I recommend specifying a system with battery storage and the ability to completely disconnect from the grid if either a nuclear exchange or solar storm appears imminent.]
The value of selling power back to the grid varies greatly with the electrical provider. Early agreements with sales back to the utility often bought power at rates much closer to their consumer sales price. Now, the purchase price offered usually takes into account more utility costs and is much lower. My co-op pays about 25% of their per-kilowatt/hour sales price. Sizing your system to provide your power needs with a bit of extra seems to be the most cost-effective. Selling power to the utility is quite often not a profitable plan. However, larger sizing may be a good way to recoup some of the cost of your system when your system usually has lower usage, such as a getaway location used only for occasional visits and vacation, but would need a larger size if/when continuously occupied later.
Solar panel considerations: Solar power panel placement is a critical decision. Panels require room. Our typical system requires an area 15 feet long by 10 feet deep by 12 feet high, with additional open area to the south without trees or buildings that would cast shade on the panels. This system has panels that tilt to adjust their angle to the sun, as the seasons change.
One interesting option is to use a sun-tracking system to move the panels from east to west so as to provide maximum solar collection throughout the day. It is more expensive and may require more ground area but it may reduce your costs and area by more efficient use of a smaller number of panels.
One suggestion to save space that you will hear is to place the panels on the roof of the home. Consider this suggestion carefully. It has the issues of putting holes in your roof, inability to adjust the angle of the panels to match the seasons, difficulty of access to the panels for cleaning, maintenance, and repair, difficulties and higher cost when replacing the roof, snow removal problems, and difficulties and higher costs when getting insurance. My assessment is that putting holes in your roof is not a good thing.
Tax considerations: At the present time, tax credits are available to offset the cost of your solar system. In our recent system, the tax credits were 30% and are available over multiple years if not all usable in the first year. This may change in future systems as the federal government works to reduce federal spending. Check what incentives are available. Our state offers a $600 grant when a solar system is installed, as well.
Advantages of a large permanent system include whole system capability from the start, tax credits and other incentives, and a system that can meet all electrical needs for multiple days of low sunlight if properly designed. Another advantage is that the design, permitting, paperwork, interface with the electrical co-op, and installation are available from experienced companies. The company should also provide you with a documentation packet of the system components, wiring, permits, and operation.
Disadvantages include size of the panels needed, project size, number of organizations involved and of course, the price. Recent news stories add Chinese hackers to the list of concerns.
8th Backup Option: A Home Hydroelectric System
Another source of motive power that can be used to drive a power generator is water power. Water power has been used to power human endeavors for thousands of years. Water wheels driven from mill ponds were all over the early USA. Large water-driven power projects, like the Hoover Dam, produced, and continue to produce, large amounts of power where the geography is suitable. There are even studies on the idea of using excess power to pump water up to reservoirs above water turbines and then running it through the turbines when power is needed.
Power generation capabilities depend on water flow and velocities. If your property is in steep country and has a year-round creek, then it is a good candidate for microhydro. While small-scale power production is available where water flow is sufficient, it is not common. If your homestead has enough water flow for year-round power production, there are modern and efficient microhydro power generation systems available that may fit your needs. Methods are available for systems using ponds and ones that can take advantage of continuous water flow in creeks and rivers. I have not studied them in depth but they may deserve study for your property if you have a suitable water source.
Our Backup Power system
As with just about everything in the prepper world, two is one and one is none. Power backup fits right in. In our case, we used an incremental approach that also offers multiple redundancies. Our cabin is supplied with electricity from a local electrical co-op. They are nice people at a smaller company that seem to care for their customers. However, they buy power from larger companies that have and control the generation plants, and are part of the nationwide interconnected power grid. Any major grid problem will affect us. We are also farther away from the power distribution substations via overhead transmission wires. When there are windstorms, we lose power. While it has not lasted long enough to result in frozen pipes, it is a problem.
We had engine-driven generators, also used for carpentry work, as an initial backup. In addition, we had a small portable power station also used for portable electrical tools. The problem with each of these is that they require human intervention to provide the needed backup. Because our cabin is not occupied full-time, the potential for long-term power loss problems definitely exists.
When a relative’s cabin suffered problems caused by frozen pipes and subsequent costly repairs, we decided that we needed an automatic backup. Given that we wanted a whole-house capable system for family vacations, possible bug-out needs, as well as future resale, we evaluated larger systems with auto-transfer capability.
After conversations with locals, especially the local power co-op, we compared two options. The co-op has local contacts with contractors for both large, permanent engine-driven systems and whole-home solar systems. We got cost estimates for both, considered power sales and tax effects, and built a year-by-year comparison. We determined that while the PV power system cost about 2.5 times more initially, after tax incentives, power generation for our use, and power generation for sale, the solar system will pay for itself after 13 years and will be money ahead after that. Since it runs on the sun and not propane, it eliminates one additional failure point. We can place the solar panels away from the road and plant cover between the road and the installed location to reduce panel visibility by passers-by. After adding lower noise to the advantages, we went with the solar system.
Therefore, we have access to power from the grid. We back up that supply with the solar system that also provides power, effectively making the grid a backup to our solar. We also have both small-engine and PV-charged portable power stations that can be used manually to power essential appliances and systems if both the grid and main solar system are down.
In addition, the main solar system also reduces our monthly power costs, and our portable systems are useful for electrical needs away from a power source. Four is three is two is one!
Wrap-up
The modern world uses electricity to the extent that it is a necessity for most people. Given the potential for grid power loss, backup is vital for almost everyone.
Multiple options exist to provide that backup. Multiple options provide a way to grow your system over time, as well as to provide “backup for your backup”.
Examine your needs, consider the available options, select one or more, install, document, and use them.
May your backup system provide the power security you need in your life. God bless. I will close with a summary checklist:
Backup Power Considerations Checklist:
What are your Power needs?
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- Voltages
- Peak Demand
- Continuous load demand
- Devices used
What backup power source makes sense for your locale and budget?
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- Engine
- Photovoltaic panels
- Microhydro
- Wind turbine
What are the costs in your area?
What can you afford, now and in the future?
Locate Electrical expertise in your area
What access to the grid will you use?
What are your noise and visibility considerations?
What are your EMP concerns?
Solar panel considerations:
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- Size
- Location/Mounting
- Sun tracking ability
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