System Evaluation and Design

“What do I need to run my home on solar power?”

This is usually the first question asked by those who are exploring the idea of using solar power to run their home, cabin, or recreational vehicle.  If you get an answer without some assessment of your power/load demand, you had best hang on to your wallet tightly!   

Although there are complexities associated with renewable products, processes and the dynamics of these systems working together, the determination of your system size is calculated mathematically.  Assessing what you want to power, when it will be powered, where the power will be located, and how long you want the power to last determines the size of your system.  The greater the effort you spend determining and identifying your load requirements the more likely your system will work satisfactorily with the least wasted expense.   

Load analysis is perhaps the most critical exercise necessary to properly size a renewable system.  Over-estimating loads will artificially inflate system costs and possibly result in an excess of material.  Conversely, under-estimating creates a system that is too small increasing the chance of system failure and decreasing the life of your system components.  Unfortunately, this most overlooked process is the cause of most failed systems!

How efficiently do you use power?

Conservation is the ultimate cost reduction contribution to a renewable system!  Turning off loads or minimizing loads result in significant and immediate cost savings.  Considerable savings in energy such as utilizing compact fluorescent lights help reduce the amount of renewable production required to replace what is consumed for lighting.  Shop tools, appliances and lights consume large amounts of power.  Although renewable systems can be designed to power large loads, the energy spent powering these loads may not be the best use of your renewable power.  Utilization of a back-up generator may be more appropriate when needed to power these excessive loads. 

Energy savings may include a refrigerator replacement, especially if it’s an older unit, with a more energy efficient model.  Another energy conservation effort example is the elimination of phantom loads, (such as clocks on microwaves, stoves, and stereo’s), can be achieved by putting these items on power strips thus enabling you to completely turn off these units when not in use.  

If you are building (or even remodeling) a house, you may want to consider using a passive solar design.  By using some fairly simple design principles, you can create a house that stays warm in the winter and cool in the summer.   These systems decrease the amount of energy needed to heat and cool your house.

How much and what kind of energy is available at your site?

When practical, the main source of energy we target is solar.  Although solar production varies considerably throughout the latitudes of Alaska, this information is measurable, predictable and can be gathered from practical observation or from looking at tables and maps of peak sunlight hours in your area.  

Because sunlight hours vary seasonally, design features and considerations may be implemented allowing the system to function when you have the least amount of sun energy production.   

The simplicity of using solar panel mounting structures with adjustable tilt angles can greatly enhance the seasonal capture of available sunlight.   Biannual tilt angle adjustments also minimize the negative consequences of winter snow coverage and enhance summers surface self-cleaning effect.   

Additionally, certain angles capturing low horizon sun and reflections from snow or water usually boosts a solar panels production beyond its rated power.   A basic requirement for any array is sturdy mounting hardware that can support the array at the desired angle, withstand on-site wind loads and other environmental assaults, and be easily assembled on site.

Wind Power

Many sites in Alaska are good candidates for wind as an available energy source.  Assuming one has obtained accurate information on average wind speed for your particular site, wind is commonly used as a supplement to solar power.  Typically, when a storm moves into an area, solar potential in lost as clouds obstruct available sunlight.  However, the storm usually brings enough wind to power a turbine at meaningful production levels.  

Most wind turbines need to be 10-20’ above nearby obstructions, such as trees or buildings.  Getting above this “surface boundary turbulence” level is critical for a wind generator to perform properly and most efficiently.  Achieving optimal heights typically requires a tower that is either free standing or guyed.   Both tower styles are commonly used yet offer both benefits and challenges simultaneously.  For example, a free standing tower requires a pile to be driven or concrete to be poured for a base.  Transportation may be difficult for the tower, materials and/or the equipment in remote areas rendering the free standing tower option less viable as a guyed tower.  

Conversely, the guyed tower is much easier to transport but will occupy a very large foot print for all of the guy wires.  Should the surrounding soils be less than favorable, the anchoring of the tower guys can be difficult.  In either tower case, the cost of the tower combined with the costs associated with proper anchoring of the wind generator tower can oftentimes exceed the cost of the wind generator itself!  Tower installation must always be designed and installed to manufacturer’s specifications in order to assure a safe and reliable wind generator installation.   

How much will it cost?

By accurately assessing your energy needs, a system can be designed to meet your power needs.  Although the ideal power system may be identified, it may not meet financial expectations or budgetary constraints.  The professionals at Renewable Energy Systems can help provide you with the most efficient and economical system design while working within the parameters of your financial budget. 

Expanding your system in stages may be an option that allows you to grow your system over time as funds become available.  Certain rural areas are eligible for system financing and grant opportunities.  Upon credit approval, we can offer competitive financing packages.

The professionals at Renewable Energy Systems can provide you the tools to properly identify your load requirements and may be solicited to assist you in your load determination.

Contact us by Phone (907)561-7941, Fax (907)561-7946, Email or U.S. Postal Mail 145 West Dimond, Anchorage, AK, 99515

30% of your total system cost may be eligible for federal tax credit!