Off the grid in four easy lessons #2

Getting off the grid even partially is an obstacle course, but surprisingly, the biggest obstacle is not technology, it is financial decision-making at all levels. From the top down, with various federal programs, down to the level of the individual homeowner, there are some severe misunderstandings and pervasive analytical blunders that generally lead to inferior projects getting priority and the best projects often never being discovered. The combined result is often an unintended subsidy to the fossil fuel industry, and unintended decreases in long-term real estate values because owners fail to uncover the financially optimal decisions for their properties. Renewable energy is generally better financially because it comes with lower operating and maintenance costs, mostly negligibly low fuel costs, for backup mostly, and usually nearly little or no maintenance.

By comparison, investments in energy efficiency, as long as you're on the grid primarily, are really not investments at all, they are about operational savings. There are many other traps, and often times they are made worse by various government programs however well intended. Not only do many programs that purport to support renewable energy barely do so, their results are often antithetical to what they claim, and the postponement of the low-carbon future is the effect. To get largely off the grid these choices need to be made very carefully.

Solar PV: green energy for the postcards to send to mom

Look ma, we've gone solar!

The Solar PV Model

It makes a nice postcard, but does it make financial sense?  Getting Off the Grid is slowed down by solar PV compared to the alternatives, but solar PV is generally easier (read: cheaper) to install. However, Solar PV efficiency, remarkable as it is, is in the range of 15-16%, while solar thermal is up to 98% efficient, in other words, you are gaining more energy per square foot by a factor of 5 from solar thermal, and the overwhelming energy demand in residential living is thermal: Domestic Hot Water (DHW), Heating/Cooling.

The main reason solar PV gets so much press is because it is easy to deploy and because there have been a lot of tax-incentives. It may not necessarily be the most sensible investment. But everything differs from property to property based on implementation details. The principal driver for PV is that because it produces electricity, transportation is easier, but that argument may not hold water if it is installed locally for local production. Also PV has been the beneficiary of a lot of tax incentives, but for residential use, it is at best a second choice, rarely the first. In short, if you own a piece of desert in Arizona, and you need to transport the energy long distance, solar PV is a great choice. For your house, maybe not so much.

Off the grid: the secrets of Solar Thermal versus Solar PV

With solar thermal, you will find conversion efficiency as high as 98%, or easily 5 times higher than with PV, but integration costs may be higher, however in most cases thermal should win out if it is properly evaluated.

The most important thing is that with solar thermal the sun's energy is captured as heat, which is directly usable for DHW (Domestic Hot Water), as well as for heating and cooling. Perhaps even more importantly, that thermal heat can be captured and stored in the cheapest battery of them all, a hot water tank. Storing energy is the single biggest (read: most expensive) problem, and with solar thermal that problem is solved. We're talking seriously green energy here, and a major step towards getting off the grid. You are now building an energy system. If you think about the cost of real estate, and the frequent limits on available space, that higher energy efficiency per square foot should not be underestimated.

Tankless water heaters: throwing out the batteries with the bath water

As a home owner, your mission is not to burn gas most efficiently, it is to increase your living comfort, as well as the value of your home. As I've pointed out in the previous post in this series, tankless water heaters, with or without Energy Star labels, seldom make any sense if you evaluate the energy infrastructure of your home properly. The example of solar thermal here makes it clear how important Domestic Hot Water can be as an energy store. Too often there are incentives, such as low-cost financing, and or tax benefits, which seduce home owners to make the wrong decisions. Domestic Hot Water as a free energy store is very valuable in the energy household of your property. Other forms of batteries tend to be expensive.

Conclusion

As noted elsewhere, when visiting salesmen come to your door, and try to sell you equipment based on tax incentives, and other programs, and showing you a fantastic payback period based on reducing your energy bills, it's katy, bar the door, and go do your financial homework first. They are interested in their commission, not the value of your property, unfortunately many counter productive government and state programs seem to reward the wrong decisions, and unwittingly favor the incumbent energy providers, to the detriment of long-term real estate values.

Only by doing a proper long-term energy plan, and evaluating the alternatives, do you have a chance of making the best decision. A 30 year model is usually adequate, given the lie spans of a lot of energy equipment, not to mention the length of a typical mortgage. Start thinking of your property as (potentially) your own private energy plant. Don't be seduced by all the incentives in the world. Remember this: advantageous financing can never make a bad project good, but it can only make a good project better.

Hopefully we will also see modifications of various program, including financing packages, which often turn on specifying Energy Star rated equipment, and very often force property owners to over-invest in the wrong parts of the plan, or make the wrong choices altogether.

Energy Efficiency is Not What It's Cracked Up To Be

A building is a system, and just like you can't save yourself rich, you can't achieve energy independence by endless investments in energy efficiency, for they are not additive, but instead, they run into the brick wall of diminishing returns on investment. Energy efficiency extends the franchise of the fuels involved, and needs to be seen in that context. They belong in the utility model.

To set up a methodology of justifying capital investment at the building level based on energy savings is counter productive to the extent that it locks us into the subscription models of fossil fuel use. The implicit and unexamined assumption of fossil fuel burning creates buyer lock in, and prolongs dependence on those fuels. This is not to say energy efficiency is not important. It is. However, energy efficiency is a secondary issue not a primary one.

We need to go back to square one, and that is the question what energy do we need? How much do we need as heat, and how much do we need as energy (electricity). After that we should look into however much energy can be generated at the building from renewable sources, solar, wind, and geothermal. Those decisions are make or buy decisions. Then comes the trade off decision of energy efficiency, namely how much can we lower installed capacity through energy efficiency. This will cause a much more constructive view of energy efficiency. It will also produce more of a systems look at the whole building.

Naturally, part of the consideration is also how can we successfully harvest peak load energy such as solar and wind energy, and in residential construction Domestic Hot Water (DHW) storage is our friend, and not the enemy, as long as we use well insulated storage tanks, to harvest our intra day needs of heat energy. Thus tankless hot water heaters are a no-no in almost all cases and should be stripped of their Energy Star ratings, because they lock us in to excessive use of peak cost energy, since they work on demand by definition, and the whole notion of the smart grid is learning to store energy and diminish on-demand usage. These devices represent a false economy which in the long run will lower the value of your building by more than any savings they could ever produce.

Throwing out the Batteries with the Bath Water

For the last few decades, there has been a gradual shift in understanding that the end of the fossil fuel era is at hand, and not necessarily because we run out - although there are of course vested interests who would like to sell us every last drop of oil, and every last lump of coal, not to mention whatever gas remains. The paradigm shift however, is about understanding that the fossil fuel era is at an end because of diminishing returns. In short the unintended consequences like CO2 emissions and other problems are the manifestations of that shift. The cost of the commodities themselves is going up because of increasing scarcity, and the cost of the various nefarious side effects are weighing more heavily all the time as well.

The other side of the shift is the increased creativity in the development of alternatives, both in terms of the technologies and in the complete frame of reference in which we operate with energy. However this process is nowhere near complete, and in the transition sometimes ridiculous misalignments come into play. One example of this is the storage of Domestic Hot Water which I have been writing about on this site. We are only just starting to understand that renewable energy means that that buildings can generate some or all of their own energy, and that the most typical renewable sources, wind and solar, are both of the peak load variety, i.e. they produce power when the weather is favorable, not necessarily when we turn on the switch. Therefore energy storage is an absolutely crucial design element in harnessing these sources. This issue has been part of the smart grid conversation for years, and we continuously hear how expensive batteries are.

Meanwhile the buyers of tank-less hot water heaters (unless as a backup heat source), are throwing out the batteries with the bathwater, or, to be more precise, by eliminating storage of Domestic Hot Water (DHW), they are eliminating the cheapest form of energy storage available in residential living, and one that is of crucial importance if we ever want to make our buildings energy independent with renewable energy. The focus in this case is on eliminating the BTU loss from hot water storage, never mind the fact that with modern insulation, these losses are negligible, and yes some space is being reclaimed. This however ignores the fact that hot water is the most natural energy storage solution, which we get practically "for free," if we realize that with various renewable technologies it is cost justifiable as part of the hot water provisioning for the premises.

This particular issue is quite absurd in its consequences. There are super efficient tank-less hot water heaters, with Energy Star labels, and they are marvelous, if heating hot water were the problem, except it is not, and therefore tank-less hot water heaters are not the solution. Rather, they are the problem. The absurdity becomes complete when we realize that there are tax incentives for tank-less hot water heaters, which means that the US government thus provides a subsidy for the postponement of our renewable energy economy by another twenty years or so, and building owners are torpedoing their best options for making their buildings energy independent. In short the very concept of the super efficient tank-less hot water heater, is of value primarily if the only option for a residential building is in consuming energy, and economizing by consuming less of it. This is the utility model, and the utility companies, gas and electric, as well as the oil companies represent this economic model, and the traditional incentives are all geared to energy efficiency more so than to energy independence.

The new model however is that energy is becoming a technology business, and buildings can increasingly generate their own energy locally, at the building level. As a result the economic value of DHW storage is now as an energy store, which enables the use of peak-load generating technologies like wind and solar. This solves the storage problem only in the form of heat, which is the largest energy demand in residential construction. In as far as the demand is for electricity, some form of battery is unavoidable if you want to rely on peak power, and come either partially or wholly off the grid.

As I have seen demonstrated over and over, the plumbers of the world do not understand that Hot Water is now going to be a freebie, and a happy by-product of this shift in energy infrastructure, in which buildings increasingly produce their own energy. This shift is particularly dramatic in existing residential construction, but   that is exactly where the greatest economic opportunity is. Accordingly, if the government wants to achieve energy independence, the incentive programs, from tax incentives to special finance programs (such as the Multi-family Performance Program from NYSERDA was one), need to take the new realities into account.

The mere accumulation of energy efficiency, which seems the only option in the utility model, is also the best guarantee that we stay in the fossil fuel economy forever, and therefore would be disastrous. Yet almost all incentive programs, with the best intentions, make this totally self-defeating assumptions. Energy independence does not happen unless you plan for it. The renewable energy economy and the utility model are two radically different economic constructs, and "energy efficiency" as a goal remains the child of the utility   model, and will prevent us from ever getting to energy independence and a renewable economy. As a dear friend pointed out recently: "You cannot cross the Grand Canyon in two easy steps." We are now at the point that we need to wean the baby from the breast of the utility companies and the oil companies, and the baby will cry at first, but to become independent, it is absolutely necessary. And there is money to be made from this energy conversion, once it is properly understood as a business opportunity.