Powering your Life

Think about all the things you use that require energy, and the sources of that energy. Appliances such as washers, dryers, stoves, ovens, refrigerators, and dish washers. Cars. Heating, ventilation and air conditioning (known in the trades as HVAC). Lighting. Home electronics, such as your TV, computer, printer, audio equipment, gaming consoles, smart phones and tablets. Typical energy inputs are electricity (which is actually a secondary energy source, having been generated by fossil fuels, nuclear, or alternative energy), natural gas, and petroleum (gasoline or diesel). 

This section will attempt to answer the following questions:

  • How do we make our “energy life” more sustainable? How can we use less energy, and generate what we use?
  • How much money can we save by investing in energy efficiency and self-sufficiency?
  • How can we make these investments more affordable?
  • What is the payback on these investments?

In this section,  I will share what I have done, my personal experiences with these changes, what I have spent, what I have saved, and what has been the payback of these changes. Over time, I will add more information to this section,  blog about specific topics, and provide a bibliography of sources for more information.

Where do we get energy?

It makes sense to first understand where we get energy, and where we use it, especially as individuals. I get much of this information from the US Energy Information Administration (part of the Department of Energy, or DOE).

First, let’s look at the Big Picture — what are the major sources of energy in the US, and how is it used nationwide. The following describes what is referred to as “primary” energy sources. Electricity is considered a secondary source, because it is generated using a primary source, e.g. by burning fossil fuels, creating steam in a nuclear power plant, or by capturing the energy of wind by spinning the rotor of a windmill.

What we see is that the vast majority — 79% — is generated by burning fossil fuels! But on the positive side (and not shown in this graph), a substantial and rapidly increasing percentage is being generated by renewable sources that do NOT directly contribute to global climate change.

So how is this energy used? Again from the EIA, we get the following chart:

So what do we see? We see that the primary source of energy in the US is from burning fossil fuels which creates greenhouse gasses (GHGs) that accelerate climate change, and both chemical and particulate air pollution that harms the health of people, animals and plants.

We see that the primary use of energy is for transportation — moving people and goods — followed by “industry”, which uses energy to make things, as well as to control the building environment (HVAC, lighting, etc.).

We also see that more than 24% of the electricity generated by utility companies from primary sources is lost in the electrical transmission and distribution system! This is an excellent argument for distributed systems (such as rooftop solar) that place energy generation closer to the point of consumption.

The major, primary energy source is petroleum — gasoline and diesel. Petroleum is used mainly in transportation — cars, trucks, tractors, motorcycles, trains, airplanes, etc. — but much is also used in industrial processes, and some of it is used in things like home and commercial generators, and outdoor power tools such as lawn mowers, leaf blowers, chain saws, and trimmers. Less and less is used to heat homes (mostly in the Northeast) or generate electricity at utility plants. 

So how do we reduce the amount of petroleum we are responsible for consuming? Obviously, we drive less, and shift the energy source for our driving from petroleum to renewable energy. In other words, electric vehicles. We can also reduce our use of plastics, which are made from petroleum, to reduce our consumption of meat, and to buy organic produce that was raised without chemical fertilizers and pesticides, most of which are derived from petroleum.

The next biggest source is natural gas, which is primarily methane. Quite a bit of methane is used by Industry, and by Utilities to generate electricity.  

So how do we reduce the amount of methane we are responsible for consuming? In a direct way, we can replace our gas appliances — HVAC systems, water heaters, dryers, stoves, and cooktops — with electrical appliances. And we save overall energy use, reducing the need for the utility to generate electricity using methane — or for that matter, coal or nuclear energy.

Once we have minimized our energy consumption and “gone electric”, we can then focus on making our own electricity.

Energy Use in the Home

The following chart shows the percentage of residential energy that is consumed by various items in the home. Note that this does NOT include transportation. I’ll get to that later. Also consider that these are averages; your consumption will be different based on the climate where you live, whether you have A/C, the efficiency of your appliances, and your habits.

What this tells us is that the first place to focus, for most people, is in your HVAC system… how do you keep the temperature in your home in a comfortable range. The next logical focus is water heating, then lighting, then “other”. 

"Negawatts" before Megawatts

The first thing you should always consider is, “how can I save energy?” This should come before considerations of how you get energy… e.g. whether you buy solar panels or batteries. It is almost always cheaper to save energy than it is to generate it. For one thing, investments in efficiency are one-time investments that pay off over time through energy savings. For another, focusing first on efficiency will reduce the amount of alternative energy and/or storage you will need to install to power your home.

Saving HVAC energy

Saving HVAC energy is involves the following steps:

  1. Improving the insulation in your home, which involves:
    • increasing the insulation (“R-value”) in your walls and under your roof
    • getting better-insulated windows and doors (such as low-e, double- or triple-pane windows)
    • making sure the spaces around your windows and doors are well sealed (i.e. caulking and weather stripping)
  2. Installing a more efficient heating and cooling system — specifically, a heat pump HVAC system, which provides both heating and cooling
  3. Expanding your “comfort range” to tolerate slightly higher temperature settings in hot weather, and lower settings in cold weather

Saving energy on Water Heating

Saving energy on water heat is pretty straight-forward: install a heat pump water heater. The best of these use CO2 as the refrigerant. While currently more costly, CO2 has two major advantages, compared with traditional refrigerants… advantages that pay off both environmentally and financially over the life of the system:

  1. It is very effective in transferring heat even in cold climates. A CO2-based heat pump can efficiently collect heat from the air even when temperatures go well below freezing, whereas a traditional heat pump requires a backup electric resistive coil even as the temperature drops into the 40s Fahrenheit. Electrical heat is much less efficient! 
  2. It has a CO2-equivalency of 1 (obviously), vs. 422 for the most efficient traditional refrigerant. This means that traditional refrigerants are 422 times more damaging when it inevitably leaks (that’s why systems need to be “recharged”) or is released from the system!