Save Water and Grow More Food

The factor that has shaped human civilization more than any other is water. The extreme weather patterns due to climate change are increasing drought in some regions and extreme storms and floods in others. In California and the West, we are experiencing more intense drought. Given this shift, irrigation practices are key to achieving optimal water efficiency on farms and in urban landscapes. Drip irrigation has been widely adopted the past few decades. More recently, a new irrigation technology called GrowStream, designed to communicate directly with plants, is starting to be deployed.

This plant-responsive irrigation system is based on an understanding of plant physiology and organic chemistry. The groundbreaking research by Suzanne Simard over the past three decades reveals the complex, interdependent underground mycorrhizal networks of forest trees and how they communicate, learn, and share. Her work is the foundation for this “smart” irrigation system. The genius of this system is subsurface tubing infused with a pore-filled polymer that can sense a plant’s needs. When a plant gets thirsty, it releases a special chemical into the surrounding soil. The microporous tubing is poised to respond to these chemicals with the slow release of water and nutrients through its millions of micropores at a rate to match the roots’ absorption capacity. When the plant’s water craving is quenched, it stops emitting the thirst chemical, and the micropores close.

Since the system is responding “real-time” to the plant’s signals, it can answer to the plant’s reaction to temperature and wind variations. Because the system is in sync with the plant’s requirements, there is less stress on the plant, resulting in more growth and higher yields. The tubing lines can run 1,200 feet, and since the tubing communicates directly with each individual plant, one line can support a variety of plant types. 

The system is easy to install and maintain; costs the same or less than other subsurface irrigation technologies; requires no sensors, valves, controllers, timers, or other electronic devices; and has no emitters to get clogged. A small machine is able to trench, roll out the tubing, and backfill in one pass. Most importantly, the efficient application of water reduces the amount needed by 30-50 percent over drip systems. Similarly, the ultra-low pressure and flow rates dramatically reduce pumping demands, yielding 40-70 percent savings on energy. 

The GrowStream system is being used in 14 countries, some in the Middle East and some in Africa. In the U.S., it is being tested on urban landscaping with the goal of increasing green cover and countering the heat-island effect. All considered, it has the potential to greatly reduce water scarcity and improve food security. The biggest hurdle will be getting farmers to change from existing methods of irrigation that are already established and paid for.

Lighting is Key to our Wellbeing

Natural and artificial lighting in our living and working spaces is critical to our wellbeing. Natural lighting normally comes into our structures through windows and skylights. Locating these openings on two adjoining or opposite walls of a room, or on a ceiling and wall produces the most effective and comfortable lighting. If remodeling or building from the ground up, it is wise to pay attention to this strategy when locating windows and skylights. Apartment dwellers have fewer options but shouldn’t automatically close drapes or blinds during the day for reasons of privacy.

We want artificial lighting to do many things: create ambiance, avoid glare, provide good task illumination, be efficient and gentle on our electrical bills, and when provided by wall or ceiling mounted fixtures, be attractive. For these reasons, it is advisable to work with a lighting consultant on remodeling and new construction projects. Unfortunately, there are not many “experts” that have combined experience in and knowledge of efficiency, effectiveness and aesthetics.

There have been big changes in lighting technology in the past several decades. LEDs (light emitting diodes) are now available with great longevity, low power usage and a wide range of color hues, even matching the beloved color rendering of incandescent lamps. Today, most LEDs are made in China. Quality can be uneven, however, as corners are sometimes cut in the push to drive down prices. Quality is always important, but especially if a bulb is to last for its advertised life expectancy.

When selecting an LED bulb, the best advice is to learn to read and understand the “Lighting Facts” label on the packaging. The two most important specifications to review are the following:

Color Rendering Index (CRI): Look for a CRI of 90 or higher. While 80 is more commonly available, this rating is linked to uneven quality and harshness of color.

Correlated Color Temperature (CCT): Most residential customers prefer 2,700K, which most closely emulates incandescent coloring. You may encounter 4,000K and 5,000K LEDs advertised as “daylight”. This may sound appealing, but most users find LEDs in this “whiter end” of the color spectrum too stark for residential use.

If an LED bulb does not have a “Lighting Facts” label, that should be a warning of a product to avoid. The Energy Star stamp, on the other hand, indicates quality.

Most, but not all LED bulbs are dimmable. If dimming is desired, be sure to check for a “dimmable” symbol on the packaging.

Lighting contributes greatly to how we feel in an indoor space. Choosing the best products is important, especially as one ages and the eyes need more lumens to perform tasks well. LEDs have taken over artificial lighting in the past decade and for good reason, but there are pitfalls to be avoided. The compatibility between switches, transformers, fixtures and bulbs is complex so working with qualified professionals helps with peace of mind.

Smart Windows Can Boost Energy Performance

Innovations in glazing technology have transformed window performance over the past three decades. Transparent glass panes can now darken in bright sunshine by means of thermochromic or photochromic films or coatings. When the temperature of the glass increases from the sun’s infrared rays, the transparency decreases, and the glass becomes clouded or frosted. With photochromic treatments, the glass occludes because of increased light intensity.

Window self-darkening coatings were adopted from eyeglass lenses that changed their tint in sunlight. These perpetually reversible rearrangements of molecules that respond to solar radiation yield big energy savings in a building’s air-conditioning demands, sometimes by as much as 25 percent. Air-conditioning accounts for about 6 percent of all electricity generated in the US, with its accompanying negative climate and health impacts.

Another similar window technology called electrochromic uses a small electric current to polarize coating crystals to create clear or frosted states. This type of glazing is sometimes called intelligent glass or switchable smart glass. It is often chosen for privacy requirements as well as for heating and glare protection.

The latest window research holds the promise of reducing a building’s cooling demand while also generating electricity. By placing a film of perovskites, a relatively new solar cell material, between two layers of glass, electricity is generated. These highly effective and inexpensive crystals are injected with a solvent vapor into the gap between the panes of glass. As temperatures rise, the vapor triggers a chemical reaction that rearranges the crystals into different shapes, increasingly opaque, while simultaneously generating electricity. This progressive blocking and subsequent tinting happen at temperatures ranging from 95 -115 degrees Fahrenheit and take only seven seconds to occur. Researchers predict a prototype window using this technology to be developed within a year.

Technological ideas to address climate change abound. Many are already making their way into the marketplace. Technological inventiveness can help us reduce carbon emissions, but to fundamentally reverse our destructive climate patterns, we need a different framework:

·         where resources are used carefully and in cyclical processes, following nature’s example,

·         where human growth takes precedence over consumerism and economic growth,

·         where equity and inclusivity are high priorities, and

·         where environmental restoration becomes an employment and societal benefit.

These and other similar tenets will restore the health of our earth and nurture its biodiversity.

Electric Homes Run Off Sunshine

Harnessing the sun for our electricity, hot water and space heating is practical and cost effective whether remodeling or building from the ground up. After maximizing use of the sun, consider going all electric, since some or all of your electricity can be site-generated. When pursuing this strategy, it is most cost effective to reduce electrical loads (LEDs, Energy Star appliances, etc.), as fewer photovoltaic panels will be needed.

Heat pumps fit nicely into this strategy. They can heat or cool a home, provide domestic hot water, refrigerate your food and even dry your clothes. Heat pumps use electricity to move heat from one place to another instead of generating heat directly. Their high efficiency results from their capacity to transfer more energy (heat) than the energy they require to operate. They are rated by COP (coefficient of performance), the ratio of useful heating or cooling provided compared to the work required. Although they have been around for many years, recent improvements greatly increase their efficiency, achieving COPs in the 2-3 range (compared to 0.8 for efficient gas furnaces or water heaters). Variable-speed motors and scroll compressors in lieu of piston compressors are key recent advances that lower energy consumption, minimize noise and reduce maintenance. Heat pumps work best in moderate climates.

For the non-scientist, heat pumps conjure up notions of alchemy: extracting heat from already cold outside air and transferring it inside to heat the home, or when it’s hot outside, reversing direction to act like an air conditioner, removing heat from the home.

Heat pump appliances such as refrigerators, dryers or water heaters have condensers built in, while space conditioning heat pumps have two main components—an outdoor condenser and an indoor air-handling unit. In recent years, mini-split or ductless units have become popular, because of their small size and zone heating/cooling capabilities. Many models can have as many as four indoor air-handling units connected to one outdoor compressor. Each zone has its own thermostat for optimum control. It is critical that each unit be properly sized for its space to run at maximum efficiency.

Mini-splits are quick and easy to install and offer great design flexibility. They are especially practical for additions and remodels. Ductless systems offer multi-stage filtration that can drastically reduce dust, bacteria, pollen, allergens and other particulates in the air.

Heat pump equipment costs the same or slightly more than comparable natural gas equipment, but if run off sun-generated electricity, the savings add up rapidly. Even if run off utility-generated electricity, the super efficiency, along with the 30 percent federal tax credit, makes it the more economical choice. I am convinced that the all-electric home run off the sun is the future.