Solar Solutions For Transportation Part 1: Refrigeration

Posted on 04/07/2020 at 12:00 by Kelly Junge


Solar Solutions For The Transportation Part 1 Refrigeration Title Graphic

In the transportation industry, the name of the game is efficiency.


Efficiency for drivers in delivering products on time and intact.


Efficiency for fleet managers ensuring their trucks operate on a budget and avoid unplanned downtime.


Efficiency for buyers whose produce shelves need to be stocked. 


Whose products need to be lining store aisles? 


Whose goods need to make it to overseas ports on time, every time.


Transportation logistics can be challenging, but if you have the right tools, the load can be significantly lightened. 


In this three-part series, we are going to dive into three transportation power needs, how those needs are met currently, and how solar solutions can help increase efficiency.


The first and perhaps one of the least apparent power needs in the transportation space is the under-appreciated battery. If your truck’s battery sits for days waiting on the next load, or months during a lull in business, you need to ensure that it’s ready to go when you are. In an upcoming post, we will explore the vital role that batteries play in powering APU’s, lift gates, and ensuring general fleet readiness. Most importantly, we will demonstrate how solar can help with general battery health, reduction in maintenance costs and downtime, and help you keep your batteries longer.


The second topic, with potentially the most moving parts, is telematics. If you have multiple trucks in your fleet and have orchestrated complex delivery routes that are dependent on particular time-based goals, you need to know where your vehicles are, and that your drivers are abiding with drive-time regulations. In an upcoming post, we will discuss how telematics unlocks a world of driver data that can improve efficiency, reliability, and safety.


The third topic, and the focus for today’s post, is the role refrigeration plays in ensuring that perishable goods arrive safe and unspoiled. A trailer full of refrigerated items represents a significant investment and a great responsibility in delivering on time. In today’s post, we are going to talk about the most common means of transporting refrigerated goods, the current and forthcoming problems, existing solutions, and why solar is perfectly positioned to help solve these issues.



  1. Reefer units have batteries to start, and if over-stressed or not maintained can be drained and not available when needed. This leads to downtime and service calls. 


  1. Forthcoming and active regulation, including new rules proposed by the California Air Resources Board (CARB), limits the amount of exhaust your Trailer Refrigeration Units (TRU’s) are allowed to emit. Drivers now, more than ever, are needing to reduce the diesel consumption of their TRU’s. Inaction to abide by tightening regulations will result in hefty fines negatively affecting company image and hurting their bottom line.


  1. Diesel expenses of refrigeration will typically rise, adding cost to transportation operations everywhere that rely heavily on fossil fuels. 


Current solutions:


  1. Plug your trailer’s battery into shore-power (this can be extremely inconvenient if you don’t have power receptacles where you park your fleet). Batteries have to be jump-started or replaced by a technician resulting in added expense and increased downtime. Ultimately dead batteries have to be replaced and installed by a technician. Not only does replacing these batteries frequently not make business sense, but it also can have a negative environmental impact if batteries aren’t disposed of properly.


  1. Reduce emissions using a relatively small scale cryo solution to replace reefer units.


  1. Devise the most efficient routes for your fleet and invest in efficient TRU’s.


Why is solar the best solution?


  1. Once installed, your TRU’s batteries will be trickle charged, so even after long periods of sitting or maintenance, your systems are ready to go when needed.


  1. More extensive solar solutions can power TRU’s partially or entirely resulting in compliance and even zero-emission operation.


  1. Along with more efficient TRU’s, the efficiency of trucking/rail is improved by installing solar and reducing diesel consumption for refrigeration. Solar systems have a 6-7year payback (depending on your state credits, etc.), and some rebates reduce the payback period. 


Tending a trailer’s refrigeration unit battery is one thing, but creating a solution that completely eliminates the TRU’s need for diesel sounds a bit crazy, right?




With the right partner and vision to drastically reduce emissions beyond growing regulations, this audacious goal is very much realistic. 


Imagine a trailer or railcar roof covered with solar panels generating 5.5kW - 7.5kW of power (see drawing below).


Railcar solar array drawing


The system would include 7kW of solar panels, a 336V 30.8kWh battery bank, a 480V 3-phase inverter, and a hybrid transportation reefer unit (e-TRU). 


This solution will end up paying for itself in ~6 years by saving diesel, and before any federal or state rebates (presently the federal rebate is 26 percent, states vary).  


In addition, this system will help meet new regulations being proposed by CARB. 


CARB is looking to drastically lower 2.5-micron particulate matter (PM2.5) and nitrous oxide (NOx) emissions by 2025 from transport refrigeration units (see figures 19 & 17 below).


One of the proposed rules for 2025 is “All trailer TRUs, domestic shipping container TRUs, and TRU generator sets must use zero-emission operation if parked or stationary for more than 15 minutes at an applicable facility and be equipped with an electronic telematics system.” A solar array and battery bank enable this zero-emission future today.


Transportation PM2.5 Regulation Graph


Transportation NOx Regulation Graph


Transporting refrigerated items is all about efficiency. 


The contents of these trailers and rail cars are non-trivial items that people all across the world rely on. Whether it’s food, medicine, or other items, moving them in a cool, controlled environment as efficiently as possible is crucial. 


With emission regulations ratcheting up the threat of unplanned downtime and expense, companies need to innovate and equip their fleets with solutions to get the job done.  


Navigating the hurdles of refrigerated transportation logistics and increased regulation can be daunting, we are here to help.


If you are looking to get in front of unplanned downtime and prepare your fleet for the zero-emission future, we would love to speak with you and design a solution to make that a reality. 


Contact us to learn more about our custom capabilities and how we can create a solar solution designed specifically for you.