HANDS ON RE LAB

RENEWABLE ENERGY NEEDS AN ADVOCATE

Over the years, it has become increasingly complex and difficult to install renewable energy systems, often due to institutional barriers. There are many materials and methods that work safely that are not permitted. Additionally, many basic items could be developed that would greatly reduce the cost and difficulty of installations. Certain items currently on the market could benefit from modification.

Renewable energy needs an advocate. The current "advocacy" that solar and RE receives seems to get the map confused with the territory. As many of us have experienced, regulations often reflect existing codes and theoretical ideas as to what is needed. Hands on workers are seldom consulted. The result is that instead of being able to do things in the most direct, safe and reliable way, the electrician is forced to "slog through every bog and scale every cliff" to follow the map he is given. Although there are easy trails to good systems, we are forbidden to use them.

BATTERY CABLES

Welding cable is an example that many are familiar with. It was used for years to make battery connections. It has proven safe and effective, but it is not "listed." The cables that are permitted are often very difficult to get, and are also more expensive. The fact that a new dwelling may be denied a certificate of occupancy until the permitted cable can be located and shipped is an additional barrier.

If a funded laboratory were capable of testing welding cable to demonstrate its effectiveness, and then take it through the listing process, it could facilitate the installation of new systems. Other types of readily available cable could be tested for suitability as well.

INVERTER DISCONNECTS

Another issue concerns the DC disconnects which are required between batteries and inverters. Currently available units have shortcomings. Trace Engineering supplies disconnects in undersized boxes. At the other extreme, there are elaborate and expensive power centers.

I have found the small Trace boxes tedious to wire. What should take less than an hour to accomplish often takes a large portion of a day. Additionally the installer can receive cuts while putting large wires into small containments, with sharp objects to work around. To put together a listed DC rated breaker in a reasonably sized cabinet at a reasonable price could take a fair chunk off the price of an installed system.

With the well established requirement for DC disconnects for inverters, it is often forgotten that systems went in for a long time before these were required, with no ill effects that I’ve ever heard of. With or without the disconnect, there is no way around working with hot terminals when connecting battery banks. The switch seems to serve little purpose.

Additionally, with the disconnect switch and overcurrent protection remote from the battery bank, the battery positive wire enters the disconnect enclosure completely unfused. It this wire were to short against the enclosure, a great deal of damage and / or personal injury could occur. The battery bank could potentially discharge its tremendous store of power in a devastating arc. The currently required systems seem to be neither the safest nor the most cost effective means of connecting batteries to inverters.

DC CIRCUITS

Often customers want DC circuits. Electricians are hampered by a shortage of listed DC lamps and receptacles. Often what is available and legal in lighting is deemed unsatisfactory by customers. Low voltage DC lamp holders require a 660 watt rating, which is available on very few fixtures. For receptacles, 240 volt models are commonly used, but it is often tenuous as to whether or not an inspector will accept them.

48 VOLT ISSUES

48 volt (nominal) systems often make the most sense technically and economically due to efficient transmission of power and smaller conductor size. Yet the rules are hazy. Battery terminals in domestic installations must be shielded, yet there appears to be no approved shielding available. Many installations are going in at 48 volts without shielding. This appears to be a code violation. This issue needs clarification, since the expense of a rejected system could put a small contractor out of business.

HEAT CIRCULATION LOADS

A standard forced-air furnace blower will quickly deplete nearly any battery bank. When installing PV on an existing dwelling, the heating system is usually the load that renders the photovoltaic array nearly useless. There supposedly are some high efficiency motors that could drastically improve the situation, but the prospect of retrofitting a system is intimidating since methods do not seem to be well established, and the listing on the furnace could be voided.

The problem of high power consumption for heat-circulation can be avoided by installing DC powered hot water pumps with boiler heating systems. These systems appear viable, yet still seem to have some issues.

VARIOUS LISTINGS

Power vents for battery boxes are not approved. Their design could stand improvement. Many other items that are useful in RE installations do not have the proper listings. Tilt up wind towers may require engineering stamps in order to pass code requirements. This list could go on indefinitely.

TESTING AND DEVELOPMENT LAB

My suggestion is that an independent laboratory be established to assess various products and get appropriate ones listed. Needed items could be developed and manufacturers could be found to produce them. Engineers could be contracted to evaluate items developed by people who have hands on experience installing and maintaining renewable electrical systems. Electrical Code writing committees could be attended by paid representatives, to advocate for rule changes where needed.

This could be done in conjunction with the RE Wrench network. Much time could be saved by studying the results from thousands of installed systems. Wrenches could be contacted to represent the hands on point of view when relevant seminars occur in their area. They could attend, with pay, in order to avoid the financial burden of lost work.

PV and wind energy systems are slowly increasing in popularity. There are some relatively simple and inexpensive things that could be done to allow for immediate quantum leaps. We are looking for interested individuals and a source of funding to set up a lab that will smooth the way for alternative electrical systems. Your input is greatly appreciated.

Sincerely,

Drake Chamberlin

(303)399-1025

Don Wallingford

Quicksilver Electrical

(303)833-4214