Solar Lighting Retrofits: Replacing Existing Grid Lights

Solar Lighting Retrofits: Replacing Existing Grid Lights

Our sales specialists are constantly requested to replace traditional grid-tied lights with off-grid solar-powered lighting systems by potential customers. This would entail taking the existing functional lights off the grid, removing all old infrastructure, installing new foundations and poles, and installing the solar lighting systems. This has always made me take a step back. What is the reasoning for this?

To understand why this comes up so often, we need to look at the three major reasons people use an off-grid solar lighting system:

1. Traditional grid power is not available, or trenching in the electric grid power is too costly.
2. Current power lines are not operational and require extensive construction to remove the current infrastructure and replace it.
3. The desire to implement a green alternative to a site, gain LEED point, or something similar

Understanding these reasons can greatly impact how you would handle the request. For example, if the existing power lines have become damaged or inoperable, then the customer needs something that can be a good replacement. On the other hand, if they are looking for a green alternative, gain LEED points, or anything like that, they may fall into one of two categories: they understand what the project will take or are testing the waters to see if solar is a good fit.

Why a 1 to 1 Replacement Doesn’t Always Work

When a potential client comes in with a request for a 1 for 1 replacement of their current grid-powered lights that are currently operational, but they want to disconnect the power grid and use stand-alone solar, this is a tough sale and rarely happens. There are a couple of main reasons for this.

Uniformity over Watts

First off, solar is rarely a 1 for 1 replacement. With the unlimited power available with grid energy, most people ignore factors such as lumens per watt, energy efficiency, etc. They think a 300-Watt light is the same across the board and is plenty bright; however, by understanding the differences between lumens and Watts, you will quickly realize this is not the case.

Lighting Uniformity with Solar

With solar lighting systems, we meet the same lighting uniformity by lowering the mounting heights of the fixtures and placing poles closer together. This allows the solar lights to provide higher lighting levels on the ground and better uniformity, sometimes even better than the old lights. 

Therefore, solar can meet the same levels with solar as with grid power, but the design, mounting heights, wattages, etc., would require different mounting locations and more. Of course, this is not always the case, but this happens as a general rule of thumb.

Design Parameters

Solar lighting system designers look at projects from the ground up to design a complete system. They look at light level requirements, pole locations, geographic location, operation profile requirements, etc. Solar specialists take many factors into account when designing a lighting system or project. This allows them to use a much lower wattage fixture and forces them to provide the best lumens per watt efficiency available.

Pole Replacements

There is also the added cost of replacing the poles. Standard light poles are typically designed to handle the fixture's weight only, so around 50 lbs. In addition, the walls of the poles are thinner than a solar light pole. They are also typically square, which is not good for a solar application.

The structure of the pole changes drastically to handle the added weight, which can be up to almost 600 lbs. The EPA of the system can be up to 25 sq ft. This is very different from a standard light pole. Without this change, there would be liabilities for the owners as the pole integrity is compromised when using the same pole. The only exception to this is a wood utility pole.

In the end, the best applications for solar include:

• No electrical lines exist at the site
• The electrical lines are damaged and not easily repairable
• Trenching the lines is cost-prohibitive
• The company is looking for a green alternative or cutting CO2 emissions
• The company is doing a complete overhaul and moving towards solar
• The company is looking to get LEED points

Using Solar to Cut Costs

The most cost-effective way to cut costs with operational electric lights is by switching the fixtures to more efficient LED fixtures. These fixtures use much less energy compared to old-style HPS lights and provide better lighting. Our partners at Hubbell Outdoor Lighting manufacture fixtures that will meet the needs of your project, and the efficiency ratings and performance of their LEDs are top quality.

Financial Incentives for Solar

Solar does provide companies with some financial incentives. These include Federal tax incentives, state and local incentives, and even some energy companies have their own set of incentives. Checking with sites such as  will keep you up to date with all the incentives and changes happening. There are even grants available in some cases.

In the end, there are many options to use solar lighting systems; however, if only disconnecting from your energy provider is the main goal, the cost of going solar can be a tough pill to swallow. Look at all your options and talk to many companies about all the variations that can be provided for your project. You may find that solar is the best option, and you may find that staying with your existing electrical system is better. Either way, we are here to help you determine the best option.