Home Power Systems: Energy Efficiency and Conservation, by L.K.O.

 (Note: This article is part of a series of feature articles about alternative / sustainable / renewable energy solutions for self-sufficiency. Previous related articles in SurvivalBlog that complement this one are "Home Inverter Comparison: Off Grid and Grid Tied" and Home Power Systems: Micro Hydro. Upcoming article topics in this Home Power Systems series will include: Photovoltaics, Batteries, Wind generators, Solar Water Distillers, Solar Ovens, and Solar Water Heating.)

Overview of Energy Efficiency and Conservation : The First Step in a viable Home Power System The most recent article in this series, Home Power Systems: Micro Hydro, in a way 'jumped the gun' a bit, since the foundation of a cost-effective, sustainable home energy system is an honest and accurate appraisal of both average and peak energy requirements. While often not as important in many micro-hydro systems - due to abundant year-round falling water in certain prime locations that can allow for less finely-tuned system efficiency - it's still an important preliminary assessment. It is particularly essential to carefully perform this crucial first step in systems relying on sun, wind or other renewable energy sources that might not be in quite as abundant supply before investing any significant time or money in a photovoltaic (PV) and/or wind-powered system. Doing a fairly meticulous power usage study (and usually re-configuring) of your home may require a bit of work and establishing new conserving habits (the 'bad news'). The good-to-great-to-outstanding news is that - depending on whether you plan to make relatively minor, inexpensive changes to your home energy loads and usage or a major retrofit or a completely new home design (including location siting) - you can potentially save an enormous amount of energy. Therefore, you will save correspondingly on initial alternate energy equipment and maintenance expense, making your family vastly more self-sufficient, in terms of energy, expense, and vulnerability to external energy dependency. Another oft-ignored benefit of down-sizing your home energy budget - while maintaining the same (or often improved) comfort, safety, security and enjoyment of your home - is that by moving yourself farther from the 'conspicuous consumption' category and grid-dependency, you also become less vulnerable and less of a target for attacks of any kind. That's hard to put a price tag on. Having less to defend can simplify defense. Yet another advantage of tightening one's metaphorical domestic power belt is that it starts paying off right away, plugging the leaks in your household's energy ship, keeping you afloat and more maneuverable financially. This often can shorten the time required to save up for the more expensive components for a Renewable Energy (RE) system, such as PV, wind or micro-hydro.

Energy Conservation: Good, Better, Best There are several levels to re-thinking domestic energy usage. We'll start with the simplest (free) actions which everyone can do, proceed to measures that require minimal to moderate expenditures of money and/or time, and finally, for those in a position to completely reinvent their living situations - either by remodeling their home, buying a carefully selected existing home, or best yet, finding optimal property and building a custom energy-efficient home. When one experiences the gains achieved by the simpler steps, it can often fuel (pun-intended) the momentum and enthusiasm for trying more involved changes, which in turn yield even further benefits, economies and self-sufficiency, a win-win scenario.

Big Picture Perspective on Typical Energy Use Before getting into specifics, it's helpful to have a good general idea of where most of the economies can be made in a typical residential energy budget. Lawrence Berkeley National Laboratory did a study in 2009 which showed seven primary household energy uses and their approximate typical percentages:

·        Space Heating: 29%

·        Space Cooling: 17%

·        Water Heating: 14%

·        Appliances (including refrigerator, dishwasher, clothes washer and dryer): 13%

·        Lighting: 12%

·        Other (stoves, ovens, microwaves, coffee makers, dehumidifiers, etc.): 11%

·        Electronics (computers, monitors, DVD players, televisions, etc.): 4%

As you can probably see from these percentages, some of the biggest energy uses (heating/cooling, water heating, and many appliances) are built into the design of most homes, so retrofitting can involve medium to high expense. However, how often and how efficiently they are used can vary widely and is included in the next section. If your main (or initial) interest in an alternative energy system is to provide just essentials that can only be provided by electricity, consider buying or building a home that has as much of the space heating/cooling, water heating and major appliances (e.g. refrigeration) provided by non-electrical means. Wood-burning stoves, passive solar and/or earth integrated home design, thermal convection cooling, and a variety of other strategies can make a well-situated and well-designed home very comfortable year-round when no grid power is available. A similarly wide variety of solar domestic hot water (DHW) heating systems and water heating coils in wood stoves are examples of non-electric (or minimally electric) alternatives to water heating. Propane refrigerators or super efficient (e.g. Sunfrost) refrigerators, while expensive in terms of initial purchase price compared with convention units, can - in some cases - achieve 'break even' status in just a few years in full-time off-grid locations when factored into the total cost (purchase price plus operating costs) of an integrated solar, wind and/or micro hydro system by offsetting the need for buying a much larger RE system. We often forget that the overall trend over time is ever-increasing utility energy costs, so trade-offs between higher initial purchase price in a more efficient energy system can - with planning - be more than offset by amortizing those costs against what would be spent on equivalent grid electricity over the life of a system.

First: Go For the Low Hanging Fruit: Conservation Ironically, our usual approach - and this goes for traditional government subsidies as well, although the trend is changing - is to rely on expensive and unsustainable sources of energy rather than doing the simplest things to conserve energy that cost us nothing, aside from a little (or sometimes a lot of) mindfulness to change everyday behaviors.

Measure Twice, Cut Once Before getting started on cutting energy waste using the suggestions in the lists below, it's often helpful - and satisfying - to measure the 'before' and 'after' performance to see how your 'energy diet' is doing. Then when you implement as many of the suggestions below (and this can be done a month at a time and compared with your electric utility bills), you can see the 'after' difference the improvements are making. These measurements can be done for many of the pluggable items in your household with a Watt-meter. Here's a low-cost meter that calculates daily, weekly, monthly or annual expense based on your current utility rates. A short, heavy duty extension cord can assist in providing access to more items when a plugin meter like this might not allow reaching some appliances and devices. Owners manuals for some household electrical devices list both standby and active power ratings. (Remember that many, if not most, manuals can be found online these days by web searching for the manufacturer and model number, so try there first if manuals are stashed deeply away or tossed long ago.) The listed ratings will help especially if you don't have a wattmeter or have a device that can't be measured directly with one. It's also interesting to compare the rated wattages with the actuals from the manufacturer's specifications to see if they are accurate. By going through your home - and don't forget outbuildings including sheds, garages, greenhouses, well pumps, etc. - room-by-room, outlet-by-outlet, you can easily estimate your 'before' usage on these items. If you've ever traversed a maze, you might have learned the technique of keeping your hand on a wall until you're back to your starting point. The same technique works well when traversing the walls of your home to find all the outlets, remembering that not all outlets are just above the floor, particularly in kitchens and bathrooms. Don't forget closets, attic fans, attic lights, basements, sump pumps, well pumps, crawl spaces and outbuildings. Wherever your house wiring goes is a potential load. Peeking inside your circuit breaker box can reveal loads that might be missed otherwise. Measure plugged loads that can be in standby mode in 'full on' and 'standby' modes, as well as 'full off' to make sure there isn't any residual current flowing. Unless you completely unplug these loads when not in use, assume the standby power is flowing 24/7/365.

Here's an article about energy monitoring that explores various options available that help show not only which items use the most electricity, but also where and when peak usage occurs. Then add in the remaining non-outlet items and estimate current monthly, seasonal and annual usage of specific appliances and lighting by noting wattages of bulbs, appliances, water heaters, Heating Ventilation and Air Conditioning (HVAC) equipment, etc. around the house, multiplied by their approximate monthly use in hours. To do a 'reality check', compare your calculated estimates with the last few years (or as much as you have if you've moved recently) of electric bills, noting the kilowatt-hour amounts on each bill. A spreadsheet such as Excel or Numbers can be handy for this. Make a row for each of the household loads, and a column for each month to track energy usage in KWH (Kilowatt hours). If you have the luxury (or necessity, depending on how you look at it) of waiting a few months (or a year or more) before investing in 'big ticket' energy-saving and/or energy-generating technology, it's often an advantage to see how your improvements are doing over the course of a year, or at least 2-3 months of typical implementation. If you just want a quick rough estimate or your energy usage, you can start with an online energy calculator or have your utility company assist you (many have services for this). These online calculators will give you rough approximations, but it's generally essential to do a full, detailed room-by-room, plug-by-plug (plus all the other loads) analysis before sizing an RE system, or even just being more scientific about your energy usage to see what's working and what isn't. If you need help, there are professional home energy audit services that can help you make an accurate assessment of your energy usage É and suggest options you might not have considered.

Example of An Energy Budget Here is an example of a 'before and after' energy budget; scroll down the page to see 'before' and 'after' spreadsheet examples and impressive improvements. Another resource for examples and case studies is Home Power magazine, which, BTW, is a superb resource for energy efficiency education as well as information on alternate energy systems, components and reviews.

Simple, Free, Easy Energy Waste Reductions Among the simplest: turning off unused lights when leaving a room, unplugging unused appliances (e.g. extra refrigerators that have don't have much in them so their contents could be consolidated with a primary fridge), unplugging chargers not in use, etc. For example, it's amazing how much needlessly wasted energy goes into 'phantom loads'; those that run 24 hours a day, but only are needed a small fraction of the time. How many chargers of various sorts run 24/7/365 in your household? and how many could be switched off when not in use (e.g., via outlet strips)? Here's a partial list (and you can probably think of many others) of free ways to conserve energy (and a more detailed list). Most of these are common-sense, every-day, obvious strategies, but we sometimes forget the obvious!

·        Turn off unused lights (at home and at work).

·        Plan reading and work times during the day when natural light is optimal.

·        Unplug seldom-used or unused appliances.

·        Unplug 'phantom loads' (a.k.a. 'wall warts'); chargers not in use.

·        For lights and appliances that have remote control or 'standby' modes, switch completely off (or unplug) when not needed; here are more details on standby 'culprits' and large 'plug loads' like wall air-conditioners, space-heaters, coffee machines, toasters, toaster ovens, clothes irons, popcorn makers, microwaves, hair dryers, set-top cable boxes, aquariums, color copiers, video games, other illuminated kitchen appliances, etc.

·        Use timed 'sleep mode' on computers and other devices instead of screen savers for devices that must be left on (for security or other reasons); set sleep start time to when you want a reminder to 'call it a day'.

·        Set screen saver start times to kick on (e.g. within 3-5 minutes) just a minute or so after your typical trip away from the computer (e.g. stretch, bathroom or kitchen break).

·        Use power strips to switch off home entertainment and computer systems.

·        Turn off all but essentials and safety-security systems when leaving for vacation É or even extended day trips more than a few hours; a good family ritual to assign to whoever is ready first for an outing to check around the house.

·        Check furnace or air conditioning filters monthly; clean or replace as needed.

·        Use sweaters, robes, warm socks and slippers or 'indoor boots' for extra winter warmth.

·        Use extra blankets in winter, and for 'kick-back' (sedentary) time in living areas.

·        Set space-heating thermostats to a low winter temperatures (and lower night-time temperatures.

·        Set air-conditioning thermostats to a high summer temperatures (keeping the difference between indoor and outdoor temperatures minimal year-round also has the benefit of reducing the 'thermal shock' of going in and out of buildings).

·        Find thermostat settings that work for everyone and don't change them; it's more efficient to keep temperatures steady than to 'throttle' or keep changing them.

·        Use fans (including whole house fans) instead of air conditioning when appropriate, and position fans to remove the most body heat; this usually allows slower fan speeds for the same cooling; small personal fans do a much better job compared to a single large fan for people a distance apart.

·        Open sun-facing shades on sunny winter days to capture solar heat.

·        Close all blinds and drapes at night in winter to conserve heat.

·        Close windows in winter to conserve heat.

·        Close daytime windows and blinds in summer to minimize heat infiltration; exterior blinds and shades often are most effective to keep heat out before it enters window glazing.

·        Open windows at night in summer to evacuate heat and allow cooling breezes.

·        Only cool or heat rooms you occupy. Close doors and vents of unused rooms.

·        Set hot-water thermostats to 130 degrees Fahrenheit, or lower (e.g. 120) if you have water pre-heaters for dishwashers and clothes washers and/or instant 'flash' (tankless) hot water heaters; large houses, particularly those with long plumbing runs between water heaters and hot water loads can benefit from these local on-demand water heaters.

·        Set refrigerators to 38-42 degrees Fahrenheit; keep full water bottles in extra fridge space to minimize cold air loss each time doors are opened.

·        Set freezers to 0-5 degrees Fahrenheit; keep extra ice or frozen items to minimize cold air loss each time freezer doors are opened.

·        Check fridge and freezer gaskets; replace those that leak air; it should be difficult to pull out a piece of paper between gaskets with doors closed.

·        Periodically (e.g. quarterly) vacuum fridge coils to keep them running efficiently.

·        Use oven lights momentarily to check on 'in-progress' cooking instead of opening oven doors more than necessary.

·        Check oven seals for heat loss and replace or repair as needed.

·        Use microwave ovens for heating water, cooking or reheating small items.

·        Cook larger meals (for leftovers) and multiple items in ovens or stove-top steamers at once; next best is to cook multiple items in a row using residual heat and/or heated water from prior oven or burner use.

·        Use larger burners for larger pots/pans, smaller burners for smaller pots/pans.

·        Use lids on pots and pans to keep heat in while cooking.

·        Use only as much water as needed in teapots, coffee makers, kettles, etc. Heating extra water just wastes energy.

·        Wash only full dishwasher loads; use short cycles after hand pre-scrubbing/rinsing any items that wouldn't get clean no matter how long the cycle runs.

·        Air dry dishes and plan run times so that dishes can air dry well in advance of their next use.

·        Wash and rinse clothes in cold water whenever possible; use detergent formulated for cold water.

·        Wash clothes in full loads whenever possible; set water level appropriately.

·        Clean clothes dryer lint filters after each use.

·        Dry light and heavy fabrics separately; don't add wet items to a load already partially dry.

·        Take items that need ironing out of the dryer before they're completely dry to minimize ironing time É and effort.

·        Use a clothes dryer's moisture sensor setting to minimize drying time; better yet, use a clothes line and/or indoor clothes drying rack. Even in winter, a garage clothes drying rack usually dries clothes in a day or three.

·        Take shorter showers or baths; a quick burst of water, followed by a 'water-off' lather/shampoo cycle, then rinsing quickly can save lots of water and associated heating costs.

·        Turn off (or fix) dripping or leaking faucets, hose bibs or other plumbing, especially those using hot water.

·        If you have an older-generation toilet, a brick, plastic bottle full of water or toilet dam (making sure none of these impedes proper operation) in the toilet tank can save lots of water; any water-saving measures are particularly important for systems that rely on pumped water for domestic use, such as well-pumps or pressurized holding tank.

·        Even if you don't have a garden, orchard or other agriculture, consider using rainwater harvesting and gray water reclamation/recycling. If you do have outdoor plants of any kind, definitely include agricultural water conservation measures and xeriscaping in your conservation planning, particularly in dry climates and/or when using electrically pumped water. Think of water usage as somewhat analogous to electrical usage, particularly if your electricity usage involves moving water around.

·        If your family size has decreased (e.g. kids off to college, etc.) consider selling larger appliances and downsizing to smaller items (e.g. refrigerators); in some cases selling newer large items can pay for the cost of smaller items (used or new).

The list above is far from exhaustive, and represents some of the more typical examples. If you think of other ways to conserve, practice and share them. The consistent cumulative and additive effect of these simple practices as a whole can really add up, more than just practicing a few of them sporadically. It's helpful to record energy usage by looking at your utility bill monthly and track which measures are in place that contribute to cost savings and energy reduction.

Low-cost Upgrades For Energy Efficiency Assuming you've implemented as many of the 'low hanging fruit' ideas above as possible, the next category to look at (now that you're already saving energy and money with the 'free' list) are low or minimal-cost items or replacements for existing electrical devices you have in your home. These can be implemented in order of greatest savings first, based on your current usage, if you've already created a spreadsheet as suggested above to itemize your current energy use and have a better idea of what to go after first. Just as one plugs the biggest holes in a leaky boat first, going after the biggest loads in your domestic energy budget can pay off the quickest. In general, before shopping for new appliances, lighting or any electrical items that might affect your energy budget, consult the Energy Star web site and/or make note of the Energy Star ratings on the appliance under consideration to find the optimum tradeoff for your budget and energy efficiency, keeping in mind the useful life of the product, payback period based on current and projected energy costs, and - very important to include - the defrayed expenses saved by not having to buy more PV panels, wind generating equipment, batteries, etc.

·        Replace incandescent lighting with Compact Fluorescent Lighting (CFL) light bulbs. Some early versions of these energy savers had lower frequency ballasts, were noisy and expensive not any more.

·        Replace incandescent lighting (particularly for task-lighting such as reading, sewing, art, etc. required for close work) with high-efficiency broad-spectrum LED lighting. Small LED lamps have become popular as book lights and can serve other purposes where extended use, optimum quality and minimal eye fatigue is needed. Here's an example of a 5W under-counter LED lamp that is equivalent to 20W halogen/xenon lamps.

·        Timers, outdoor motion sensors, indoor occupancy sensors and dusk-to-dawn light sensors can all minimize lighting 'on time', regardless of the lighting technology used (although CFLs don't work well with some switching technologies).

·        Replace older Cathode Ray Tube (CRT) televisions and computer monitors - if you still have any - with energy-efficient flat screens.

·        Repair or upgrade weatherstripping, caulking and other building components and interfaces that subject your home to significant heat loss/gain areas due to infiltration. Don't forget attic crawl space air leaks. Utility companies often provide or recommend services such as infrared photography (e.g. FLIR) to spot the most egregious energy loss culprits. If you already have access to infrared night-vision equipment, you can scope this out yourself, both indoors and out to find trouble spots. Here's an economical tool to assist in the detection of thermal leaks.

·        Water heater blankets can improve the energy efficiency of both electric and gas-fueled water heaters, and benefit both older and newer more efficient models.

·        Install low-flow shower heads and sink aerators (if you haven't already) to reduce water consumption, particularly hot water use.

·        Low-wattage hair-dryers are probably more important in planning for peak loads, but they can also impact average load calculations and savings, too.

·        Add movable exterior shades (many of which can be easily rolled up to allow evening summer breezes) to minimize summer heat gain.

·        Use area rugs over bare floors to add insulation. The psychological effect of warmer winter feet can minimize the temptation to nudge thermostats upward.

·        Add strategically placed landscaping (trees, trellises with dense seasonal foliage, etc.) to provide summer shading and maximum winter insolation (heat gain through glazing).

·        Replace desktop computers with laptops when possible; if occasional extra 'screen real estate' is needed. Switch on external monitors only when needed, for both laptops and desktop models.

·        For privacy, use light-diffusing sheer curtains to let in winter light and heat but obscure visibility from the outside during the day as needed, then use heavier curtains (with high insulation value and magnetic seals around window frames if possible) at night to keep heat in.

·        Add or enhance home insulation in attics, walls, under floor crawl spaces, etc. Since the greatest heat loss (and summer heat gain) is through the roof, this is the usually first place to start before enhancing lower spaces. A licensed insulation contractor can both recommend and install the needed insulation to match the optimum tradeoffs for your specific home situation.

·        Replace single-pane windows and glazed doors with double-pane or triple-pane glazed units, including skylights. Add storm doors and windows where they can add extra insulation value.

If you want to get even more scientific about which energy loads are consuming the biggest (or smallest) portions of your household energy budget, a Watt-meter is a good investment. Here's an inexpensive Watt-meter to measure periodic energy expense based on current utility rates.

Major Home Remodeling or New Construction The last category of home energy improvements typically applies only when one has the good fortune to be able to do a major remodeling project, or best of all, a new construction on an ideally situated parcel of land. There are a number of general strategies that can be employed to make new homes (and major remodeling projects) particularly energy efficient. As one might expect, implementing as many of these as possible will realize the greatest potential energy savings.

Passive Solar Design: Orientation, Insolation, Thermal Mass, Insulation The general idea of passive solar design is to maximize winter (or summer below the equator) heat gain and minimize it in the opposite season. In some locations the sun's power can provide all the heating (and often electricity via PV panels) required if adequate insolation (sunlight entering the building), thermal mass (heat storage) and insulation (means for keeping heat from moving in or out of a structure) are available in appropriate places with appropriate control mechanisms. Typically, windows should face true south (ideally within 10 degrees) or north in southern hemisphere locations. Natural obstructions such as hills or trees should be minimal in the path of the winter sun, and it can be worthwhile to carefully select a site on a given property to optimize the total winter sun exposure. A solar site selector, using a compass, bubble level and tripod can be used to map out obstructions in proposed sites during different seasons (e.g. solstices and equinoxes) to choose the optimum home site. Together with statistical weather data about a proposed site's potential (such as degree day maps and degree day data) one can predict approximate solar potential for a given site for various times of year. Good passive solar design may incorporate movable elements such as adjustable overhangs that let in just the right amount of sun for each time of year/day, and/or seasonally variable foliage such as sun-facing arbors or deciduous trees and shrubs that provide summer shade, but let most of the sun in during colder months when leaves have dropped. Combining site selection with careful window sizing, ventilation characteristics and placement will afford the optimum design solutions. There are free software tools such as those provided by Sustainable by Design to calculate sun angle, position, path, overhang design, analysis, horizontal and vertical shading, window heat gain, etc. As always, if the technical aspects of any part of these processes seem daunting, get professional help and also use online resources to complement your knowledge and expertise. Once the sun enters your home, it must heat adequate thermal mass. Good candidates for this heat storage include traditional materials like adobe, tile or water in containers (the darker the better to aid in heat absorption), as well as creative options such as passive solar slab cement floors (which can be colorized, scored and grouted to look like tile. The importance of thermal mass is often underestimated with less than satisfactory results. Skimping on thermal mass can mean the difference between a home that is chilly (read: expensive) in the morning and overheated in the afternoon vs. one that has a comfortable temperature that doesn't vary much from one time of day to the next. Think of thermal mass (some times called a thermal flywheel using the metaphor of a wheel's momentum) as your passive solar system's heat battery.

Most modern homes are well insulated, but in many cases a super-insulated home (such as a monolithic dome) can offset other negative factors, such as low thermal mass or insolation. Needless to say, adequate-to-above-average insulation is usually a prerequisite for any good solar home design. One way of achieving superior insulation by using local indigenous materials is through the use of earth-berming, often most evident on north-facing walls. If your intent is to combine passive solar home design with photovoltaics, the selection of the site should address the roof angles (e.g. large surface area facing due south) and amount of sun received by either roof-mounted collectors (typical) or remotely ground mounted panel arrays. To combine wind and solar, it might require finding a location close enough (to minimize power losses from long electrical cables) for both PV panels and wind generators to receive the sun and wind required. Different site considerations need to be factored into an integrated design when contemplating optimizing for solar (space heating and PV), optimizing for wind generators, and optimizing for micro-hydro systems.

The simplest solar design approach makes for homes that are long along the east-west axis and typically 1 room deep (or not much more than that) along the north-south axis. For homes that are more than 1 room deep along the north-south axis, it helps to carefully consider both air circulation - which optimally can be achieved by natural convection or, next best, efficient fans and/or ductwork - and daylighting. Skylights, light tubes, translucent doors and clerestory or transom windows can assist with getting light back into northern rooms and minimize the daytime lighting needed. Another technique deserving mention is the use of vestibules for entries to minimize heat gain and/or loss. Commercial buildings often make use of this method of minimizing the amount of lost or gained heat each time an exterior door is opened, and it works well for homes, too. Entry vestibules also make great laundry and/or mud rooms as well as coat, boot and other storage areas.

Early in the design phase, if possible, minimize long plumbing runs between water heaters and hot water loads by consolidating plumbing runs along a single wall, as short as possible. This also saves on initial plumbing costs as well as ongoing expense due to heat losses, as well as time wasted waiting for warm or hot water. If a bathroom or kitchen far away from the water heater is unavoidable, consider an on-demand, tankless hot water heater for those locations, to eliminate running taps for up to several minutes to bring water to the desired temperature. For passive water heating, also consider, if possible, locating a renewable source of hot water lower than intended loads and keeping plumbing bends to a minimum. This can often allow for a completely passive 'thermo-siphon' system where the circulation energy (a convection loop) is provided by the temperature differential between the warmer source (e.g. DHW solar panel or wood-stove embedded water heater) and the cooler water in the bottom of the storage tank. Some thermosiphon solar DHW systems integrate the heat source and storage tank for optimum efficiency. If a thermo-siphon hot water loop isn't feasible, choose an efficient pump to circulate the water or other heat transfer medium.

There are a wealth of books, web sites and other resources on the subject and it's best to pick a design strategy optimal for your particular location, climate, budget and locally available building materials. This article just touches on a few of the ideas important in a well thought-out energy efficient home design or re-design; consult experts to get even more ideas and do reality checks on concepts and techniques that you're considering for incorporation in your next home. You can also elect to have energy-efficiency professionals install various components of your home energy systems as well as assist with the designs and component/appliance/device selection. Don't forget to explore any and all federal, state, regional or local energy efficiency rebates, tax credits, etc. These can be substantial depending on the energy saving technology being considered and include biomass stoves, efficient HVAC systems, insulation, roofing, water heaters, windows, doors, PV and wind turbine components, geothermal heat pumps and other items. These can be significant and potentially offset much of the initial financial outlay for the specific item(s) used. Sooner or later, one reaches a point of diminishing returns for scrutinizing home power expenditures, but there are lots of things you can do, regardless of your financial budget, to optimize your energy budget. All these improvements improve your economic and self-sufficiency bottom line, regardless of if - or when - these enhancements go toward a renewable energy system installation.

Additional References
Getting Started with Home Efficiency Easy Efficiency Improvements Pay Off

Passive Solar Home Design Making Your Home Water-Smart

How Does Your Home Measure Up?

Beyond Your Utility Meter

How to Reduce Your Energy Consumption

Passive House Institute US

Vendor Contact Info
Here are a few manufacturers of home energy efficiency technology products; there are many more online:

Find ENERGY STAR Products

Home Efficiency Equipment and Products

Renewable Energy Businesses in the United States by State