The first challenge when entering the renewable energy industry is understanding how to design and install projects. These articles are dedicated to teaching you the basics of how to design and install solar PV, solar thermal, and geothermal projects.

If you’re brand new

Click here to learn what is NABCEP and wether or not you should need to get the certification. If you’re serious about the solar industry and you want to get the NABCEP Certification, but you need to understand how exactly to apply, you can read more about getting the NABCEP Certification here.

Articles That Will Help You
A Review of Solar and Geothermal Certifications, Licenses and Permitting
Solar Thermal Design and Installation Guide

Solar PV Design and Installation Guide
How to Design a Solar PV Array and Estimate Power Production
Geothermal Design and Installation Bundle

How to Design a Solar PV System 101: The Basic Terms

Want a basic technical understanding of solar PV project terminology? Read on…
If you’re an experienced installer, none of this information will be new to you. If you’re new to solar, it will be helpful. But keep in mind, we’ll be skimming the surface.

We’re going to begin with the basic terms. This is very important for design because you need to understand the concepts before you start applying real numbers to a design. It will also help with sales because it will help you explain some basic concepts to curious customers.

Performing high-quality and efficient site visits is absolutely critical to the success of profitable solar projects, especially residential projects. You need to be able to capture all of the information you need to quote the system correctly, design the project, and tell the installation crew what to expect. An efficient site visit process will lead to smooth operations and profitable jobs while a complex or disorganized process can lead to unprofitable jobs and a lot of confusion.

Power

Power is an AMOUNT of energy. It’s the measurement of energy, measured in kilowatts (kW). Power is measured in an instant. Most of the sizing done in solar PV design (conductors, inverters, fuses, etc.) is based on how much power will be passing through a specific component of the system. Because power is measured in an instant, it can vary widely over time and from minute to minute.

Power (watts) = current (Amps) X voltage (volts)

Energy

Energy is the is the actual work done by power. It is measure in kilowatt-hours (kWh). Consumers pay for kWh. It’s a measure of power over time.

Power (kW) X Time (hours) = Energy (kWh)

Current

Electricity is the flow of negatively charged electrons. The current is the amount of negatively charged electrons in a specific part of a circuit.

Many people find it useful to use a water analogy when discussing electrical terms. In the water example, it’s useful to think of a dam with a pipe at the bottom where water can flow out.  The amount of water that can pass through a slice of the pipe, in other words the area of the cross-section of the pipe, is analogous to electric current.

Voltage

Voltage is a measure of the force or pressure of the electric current in a circuit. It’s measured in volts.  Electrons of the same material WANT to be homogeneous, i.e. they want to be evenly spread out. Thus, if one area has less electrons then another, the electrons will move in an attempt to equalize. This flow is what created a voltage potential and causes electrons to move.

To use the water example again, if the size of the pipe at the bottom of a dam is a measure of current, the height of the dam is a measure of voltage. Higher water behind the dam creates more pressure.

Resistance

Electrical resistance is the resistance of the flow of electricity through a conductor. It does not reduce the current flow of electrons (how many electrons there are in the circuit), but it does reduce the voltage (how fast they’re going). It is measured in ohms.

Voltage Drop (volts) = Current (amps) X Resistance (ohms)

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April 17th, 2012|Categories: Geothermal and Solar Design and Installation Tips, Solar, Solar Design & Installation|Tags: , , , , |
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5 Tips on Designing Vertical or Slinky Geothermal Loop Fields

We’ve found it useful to focus on both articles that will help companies with their sales and marketing AND design and installation. A few weeks ago, I shared a piece – thanks to Ryan Carda – on geothermal flow path analysis for ground loop design that came from a discussion forum from our advanced geothermal design course.  My plan is to share more technical discussions that are happening within the course. If you are installing or designing geothermal projects, these articles will be useful to you if you never take the training. This is my goal.

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Here are a few tips on on vertical and slinky bore design.

Vertical Bore Design

1)      The target (optimum) flow rate versus pipe size is:

2.8 – 3.2 gpm per loop for ¾” loops
4 – 6 gpm per loop for 1” loops
5 – 9 gpm per loop for 1.25” loops

Staying within those flow ranges per loop will keep you well below the maximum recommended flow rate for head loss (4 ft per 100’ of pipe length, Figure 5.4) and above the minimum flow rate required for turbulent flow.  For the vertically-bored design, I recommend using two loops for 6 gpm per loop with 1.25” pipe.

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February 22nd, 2012|Categories: Biomass, Geothermal and Solar Design and Installation Tips, Geothermal Heat Pumps|Tags: , , , |
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HS TV Ep 8: 1/2 the Drilling Depth, 1/3 the Footprint, SCW vs. Closed Loop Geothermal Systems

Standing column well geothermal projects have significant advantages over closed geothermal projects in certain circumstances. Standing column wells typically need half the amount of drilling then traditional closed systems, because they can transfer heat so much faster. Also, they be installed in places with extremely limited space, in cities for example. Lastly, they can be used in rural areas in conjunction with potable water wells.

The problem is that because even closed loop geothermal systems are foreign to many HVAC and drilling contractors, standing column well systems seem like they’re on another planet. We’d like to change this.

We’ve been writing heavily about standing well systems, how they’re designed, their difference between closed system systems. See below for some review articles if you’re brand new.

The 4 Differences Between Geothermal Standing Column Well and Closed Loop Systems
What You Need to know About Quoting and Selling Standing Column Well Systems
13 Steps to Basic Standing Column Well Geothermal Design

I also wanted to speak with Dr. Albert Koenig, a standing column well expert, to get his opinion on the technology, if he feels it get be relegated from a niche technology and what he is doing to demystifying the design and installation process so more contractors will feel comfortable designing and installing the technology.

Here are the highlights. 

SCW systems typically need 1/2 the drilling length of comparable closed loop systems, because the thermal conductivity is extremely high in SCW systems.
SCW typically take 1/3 the foot print of closed systems, if you’re space constrain this will be extremely attractive.
SCW systems can typically 12 to 15 tons of heating and cooling capacity for each well, compared with 2 tons be average for closed system systems.
Most well drillers know 80% of what they need to drill and installed SCW wells.
You can retrofit existing water wells for a SCW project, but you may need to increase the depth of the well.

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February 7th, 2012|Categories: Drilling, Geothermal and Solar Design and Installation Tips, Geothermal Heat Pumps||
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[Video] How to Select Solar Hot Water Components and System Types

In this video, author and ISPQ Certified Master Trainer Bob Ramlow provides a detailed outline of common components found in solar thermal systems, and the four most common types of systems.

February 5th, 2012|Categories: Geothermal and Solar Design and Installation Tips, Solar, Solar Thermal|Tags: , , , , , , , , |
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The 4 Differences Between Geothermal Standing Column Well and Closed Loop Systems

There are four major differences between standing column well (SCW) and closed loop geothermal systems.

The use of exchange fluid
Loop materials and characteristics
Use of heat exchangers
Applications of the technology

To learn more about standing column well design, download the 13 steps to basic standing column well design by Dr. Albert Koenig here. 

 

1. The Use of Exchange Fluid.

The fundamental difference between the two systems is the exchange fluid used to affect the heat transfer.  In the case of grouted loops, the working fluid is water with an additive (typ. methanol) contained in the closed HDPE pipe loop that runs from the well to the building.  In the case of SCW, the working fluid is well water which fills the borehole from water bearing zones (WBZ) intersected by the bore.  There are advantages to each of these design approaches.

2. Loop Materials and Characteristics

The grouted loop provides a continuous leak-tight HDPE wall that is guaranteed for at least fifty years free from defect that requires little to no maintenance.  But, this comes with a heat transfer penalty, in that, the plastic wall together with the surrounding grout filler, impose a thermal impedance on the transfer of heat to the bore wall.  This is further limited by the HDPE pipe size that can be comfortably be manipulated down the bore, representing approximately 40% of the bore wall surface area.  Moreover, the installed loop upcomer and downcomer are not thermally isolated, allowing heat to be shunted, rather than transferred to the bore rock for storage.  The net effect of these limitations to heat transfer is to require twice the drilled footage for a given project than SCW design.  This is predicated on achieving the same working fluid temperature.

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January 31st, 2012|Categories: Geothermal and Solar Design and Installation Tips, Geothermal Heat Pumps|Tags: , , , , , , , , , , , |
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