Solar Heat

THE KSD “SOLAR SAVER” HEATING SYSTEM

Preface: 25 years ago I defrosted a freezer every four months. Two years ago we had a malfunctioning freezer that needed regular defrosting. Today our new freezer doesn't need any defrosting at all. I say this because the biggest engineering obstacle for solar heat storage and for solar-based coolness storage is moisture buildup. Take heart, because the refrigeration industry once faced this same moisture buildup problem and they effectively fixed it.

I combine a mini split heat pump with a rockbed to deliver both heat and hot water on demand. Our goal is inexpensive 90% solar, 10% renewable electricity to run the heat pumps and 0% fossil fuel or biofuel, with a heat setback at night for smarter energy performance and then a reliable 68 degrees by 6:00 a.m.

I know of one other solar system on earth that can deliver anywhere near this level of renewable energy performance, if at a high cost. The Drake Landing housing development in Alberta puts heat into a vast heat sink all summer and draws on it all winter. If you don't happen to have an entire community with plenty of spare land to use up, then perhaps I should help you. It's far more cost-effective to bank about 3 days worth of solar heat in my unique rock bed design, than it is to bank a whole season's worth of heat in the ground, where much of the heat slowly leaks out as the months pass.

I expect that the new renewable standard will be 90% solar. If you plan on purchasing or building an edifice that achieves far worse than this energy standard, then you will have stuck yourself with a long-term unprofitable building and you'll have to pay the stiff carbon tax. Renters want that climate change cachet, which happens to be good for own their bottom line, and that's going to permanently affect your rental prices and the building's eventual resale value.

Solar Thermal System Opportunity.htm

Solar Thermal System Opportunity.doc

The KSD “Shade Mount”,
One Design Alternative to In-Roof In-Attic Mounting
The rock bed is below the collector on the left side
Heat collection systems, as opposed to PV systems, are relatively unaffected by branches shading the collector

KSD “SOLAR SAVER HEAT/HW SYSTEM PRODUCT OVERVIEW

Active solar air systems of the 1980s had three critical engineering problems: they blew mold, radon and dust into the building. We're different. Heated air is pumped in a closed circuit through multiple solar heat collectors and then down to rock bed storage. Any moisture in the system is inherently evaporated and then the moister air slowly leaks out. For hot water we slowly, sometimes over a 24 hour period, move the heat into water. We never have any chance at a mold problem because nothing but heat pump fluid and heated water enters the building..

Shade mount air collectors may not be as space-efficient for moving heat as water per cubic foot of air, but air avoids all sorts of added water expenses and maintenance issues: freezing, rot or rust due to leakage, boiling. Air is already a standard heat transmission medium in many forced air HVAC systems.

Our solar heat collector is designed to avoid problems.

• We have avoided any possible boiling or freezing in our heat collectors. We expect no ongoing maintenance issues such as glycol replacement.
• Our heat collector has one moving part, the fan blades. If the collector is focused due south, southwest or southeast, it will still work. If tree branches cut heat absorption by 10% in December, solar thermal will still work.
• The system's heat collection function continues through a prolonged ice storm-caused blackout because the collection function is driven by its own small, off-grid PV panel. The entire system will work throughout a winter-long city-wide natural gas disruption. You can be completely off-grid and at 68 degrees if you have a reasonable amount of battery backup to run the heat pump.
• We aim for easily replaceable and recyclable parts. We use glass.
• For heat on demand, we have adapted a mini split heat pump to our needs. We also can preheat water, often to hot water temperatures, within the same solar heat storage box.
• My rock bed (shown) is energy-efficient in its heat storage. We don't waste energy unnecessarily on air friction issues within the rock bed. It turns out that almost all buildings already have a far cheaper place to store multi-day solar heat, and a heat pump can even out the cool hours versus hot hours with remarkably little electricity use.
• The shade-mount frame, as shown in the picture, is engineer-rated for 110 mph wind gusts. In the end we overbuilt the frame with thick aluminum. Moreover, the wind spill holes that we built into the frame are able to spill wind gust overpressures, and the frame is situated two feet away from the building at a 45 degree angle. My hope is that the frame won't blow down before the building itself blows down in a category 5 hurricane.

Our patent-pending solar heat collector economically retrofits many buildings while creating nearly zero maintenance issues. We're the first economical product on the market to fill this niche.

PRODUCT COSTS

Good News ! Our initial price is close in lifetime costs to conventional fuel systems, with low ongoing costs! Fossil fuel systems require expensive annual inspections, simply because fossil fuels by their nature can cause big fires. Solar just works and works.

Return on Investment : Our best estimate at this time is that a $15,000 installation on a typical house will provide an 80% replacement of fuel with solar. For heating oil at $4/gallon in New England, savings could be roughly $1250/year, or an 8% annual return on investment. For larger complexes, size-efficiencies will create a 10% annual return on investment versus heating oil. For larger buildings, going after the easiest 20% of solar heating and heat storage produces an even better return. On top of these prices, federal or state solar tax credits may be available.

Retrofit Advantage : We can retrofit most buildings. Many existing homes have uninsulated attics, and if south-facing shingles on the roof are replaced with greenhouse glass surfaces, attics can accumulate heat. Existing houses can use current heating units for their back-up need. Our unique carport mount (shown) can provide easier cheaper solutions for sites with challenging roofs.

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MEETING 90 PERCENT OF HEATING NEEDS

Solar heat supply and a home’s total heat and hot water demand don’t always match. We maximize fuel displacement while minimizing costs. Increasing solar supply, and/or solar heat storage, helps to cover more of the fuel demand curve.

Because of random variations both in winter sunshine and in a homeowner's needs, no solar system alone can cost-efficiently cover the last 10% of fuel demand. Current heat pumps are going to use the electricity equivalent of about 9% of your house's current fuel needs and straight up heating with electricity will make sense on one or two days per heating season. Note: I'd love to develop an electricity-saving mini split heat pump especially for heating our solar houses and office buildings, to further displace the system's use of non-solar energy.

Solar Availability Versus Solar Demand

We optimize our system for winter solar collection so that we can meet our customers’ extra December needs in a cold, cloudy month. Our rock bed storage unit helps to match fickle solar supply with homeowner demand. In summer, our outdoor heat storage unit doesn’t add to the customer’s air conditioning load and our indoor rock bed is well insulated, so it still reduces hot water fuel costs. Some homeowners will choose to heat their swimming pools or hot tubs with excess solar hot water generated in summer. Tell us about your specific needs!

At some time in the future, KSD should look into developing a solar-powered 24/7 air conditioning system. Direct solar-powered cooling through the use of a phase-change coolant has been accomplished elsewhere. The same type of rock bed should handle the job. As with my current West Greenwich greenhouse, inherent dehumidification can be built right into the cooling system.