I’ve been thinking of a solar-powered solution to run a LoRa-Gateway 24/7 on solar-power. The Gateway as well as the solar station should be outside. I was thinking of using this gateway from dragino:
The manufacturer reports a power/current consumption of 12V, 500mA or 6W.
I’ve been thinking of using a 50-100W solar panel along with a solar charger or even a MPTT tracker and a 60Ah solar battery.
What are your opinions?
Here are references of people that have tried this already:
My opinion: Why Not? Depending on where you are the sun has enough energy to charge the battery. My (indoor) Dragino LPS8 has a power consumption of 4.5W so 6 W as a first estimation is ok. I would make my own measurements, the rest can be calculated. The battery could be AGM or LiIon but take care of low temperature.
An additional node could measure battery voltage and charge/discharge current.
Have fun!
…and dial down the tx PWR to min(?) to avoid creating the classic near/far problem as likely will be on SF7 by default due to proximity and need to minimise on air time…
Thank you or your reply cults! The backhaul has to be cellular/LTE, The availability is rather best-effort than 99.95%. The project is deployed in South Germany.
The gateway should be deployed the whole year at temperatures of -15 to 50°C (estimated).
Be carefull with the batteries. They dont like neither high nor low temperatures. Especially LiIon tend to make problems at low temperatures. LiFePO4 can be a better solution - look into the datasheet.
Hi @ecosoph, I recommend that you start as follows:
Set up all the equipment you need (gateway, backhaul, remote ops, battery sensors, etc.) using a lab/bench power supply and check that it all works OK for 2 weeks from 11.5VDC to 18VDC as this is the voltage range that will come out of the PV/controller/battery system.
Measure the stable and peak current draw at 12VDC.
Look for suitable safe locations where there is unrestricted view of the Southern sky with the sun well above the skyline all year.
The alternative, of course, is trial-and-error but that is a hard school for off-grid power.
South East for the win - you get your battery charged in the morning and the residual solar runs the unit for the rest of the day so you start the night with a full battery.
Attached some pictures of my setup using a solar powered DLOS8.
This was built for a temporary deployment during summer, but not used in this way because I found a location with acces to mains voltage.
The solar panel is 25Wp, the batteries (2 in parallel) are 12Ah lead acid.
There is a MPPT solar charge controller, and a LoRaWAN node based on Pro Mini which monitors battery voltage (with antenna output fed into 50 Ohms resistor as suggested above).
Current drain of the DLOS8 was measured 0.27A at 12.5V (3.6W) with WiFi backhaul.
I found the DLOS8 unproblematic to setup and stable in operation.
I am not too impressed with 12V cable connection in the bottom of the unit. There should have been some cable gland or other form of stress relieve.
The 25Wp panel provided plenty of power during the summer months, but is now (end october) no longer able to keep the battery charged,
But this is for Norway, Oslo area. South Germany should be easier.
Thank you ArthurK, that is a nice and professional looking case. Where did you get it from? Did you cut the foam yourself? The gateway shown there is rated with 12V, 500mA, I’m thinking about using this one rated with 12V, 1A:
According to some solar calculator by a reliable German tech retailer:
Here is the calculator:
I should use minimum 85Wp and a 120Ah battery.
I was thinking of getting a 150Wp panel as they are not too expensive.
I found the case at a hardware store in Norway. It is this one: case
This type of case is generally known as pelicase (which is actually the brand). They come in different sizes and are typically used to transport e.g. photo equipment. The original pelicases are quite expensive, but you should be able to find an ‘own brand’ in a hardware store. The foam is pre-cut in small pieces (dices) and can just be pulled out to make the hole dimension that you want.
I do not have experience with the LG308 gateway. Obvious disadvantage as compared to DLOS8 is that you still have to put it in an IP housing for outdoor use. I should hope (and expect) that it uses less than 12W. As mentioned, DLOS8 uses well below this and the electronics inside should be comparable,
85Wp sounds like a reasonable proposal. You would have to account for the worst period in winter, when there is no sun for 4-5 days or so. You should be able to find statistical solar data for your location. More power is nice of course, but will also require stronger rigging, foundation etc.
Thank you for sharing the pictures of your mobile solar-powered gateway with us.
Here are some hints:
Make sure, that is solar charger is suitable for AGM-batteries. This kind of batteries should be fully loaded up to abt. 14.5V (depending on the temperature) in regular intervals (e.g. once a week). If you don’t do that the battery will loose its capacity.
If you want to have a better coverage, mount the antenna on top of the mast (antenna should be as high and as free as possible).
PS: An additional hint: use an appropriate fuse between the battery and your installation. These batteries can have short-circuit currents up to a few hundred ampere. I would not like to see your nice gateway burning.
Some essential suggestions from @wolfp, I’d add that when you have batteries, cable management is essential too - as in tidy, appropriate length & secure.
Even small Alkaline batteries can go wrong, as observed in a class of 9 year olds, one who shorted out a 4 x AA battery pack by twisting the red & black ends together. That was a challenging five minutes getting it to the playground sandpit without too much excitement.
Thank you guys, I’m happy about the helpful resonances, I’m sure other people will also get back here when designing their solar-powered gateways. @wolfp thank you for the fuse hint! @CRIJapan that’s a nice setup, I’ve also got two of those charge controllers that are very cheap and can also be used for AGM batteries. The size of the solar panel and the 10Ah look a bit underdimensioned to me but in sunny regions it might be fine and for many applications you don’t need to have 24/7 lora coverage.
I like the systems over here!
For a project I’m going to put up 16 of the DLOS8 gateways in Germany and Italy in rural areas. All on 4G.
Do you know how much data you use on a gateway?
!