Off Grid Charging Setup for Starwind5 with Solar: Always a Slave…

Setting up your Starwind5 with Solar is easy. Any Third party wind charge controller from a reputable supplier like Midnight, Missouri, Schneider, Siemens, etc, can be used as a DC to DC charge controller directly to batteries. However when looking to integrate the Starwind5 with existing Solar charge controllers to help top up your batteries, its important to get the hook up right. This short note, provides an overview of how to successfully integrate your Starwind5  as a “slave controlled” power generation element into your existing or planned Solar generation facility and, we also review what your choices are for communications networking between your controllers and other input and remote monitoring and control devices. The good news is it’s all doable, just keep in mind success is in getting the details right to your budget.

To start let’s use the hi tech Wind to Solar Integration example you will need to follow when using “Tier 1″combination charge controllers from companies such as Schnieder(Xantrex) or Siemens, or even Eltek (mobile telecoms.) First each vendor has a communications bus for monitoring and controlling the state of their own charging and grid connection power outputs and inputs. The monitoring and control interface also has one or more external physical connection(s) to allow the integration of external PCs and other control and monitoring equipment to create a small private control network.

These interfaces are often provided in different physical formats with different signalling formats controlled by their internal software programs. The basic network communication types used for power control and monitoring are as follows:

Canbus: Originally the “Car Area Network  Bus”  Canbus evolved from a proprietary industrial protocol network scheme originally created by Fanuc of Japan, which later became GE Fanuc, who then released their industrial control bus standard into the public domain. Canbus is found in many third party monitoring and control products, hardware and component hardware as it is relatively cheap to produce and wel known in the world of industrial control, having migrated from just the automotive world of cars and trucks into general industrial control use over time. Canbus is fast, can be programmed best in application requiring real time response and has a number of software companies supporting canbus with sophisticated  real time adaptive control and monitoring schemes, software which is most often licensed into larger vendor products as part of the supply chain build of more complex systems and products, like charge controllers. Electricans have been trained on canbus for years and this can often be the deciding factor in Solar and Wind charge controller network equipment interface selection. Not everyone in the electrical trade is an IP (Internet Protocol) expert.., at the moment, so canbus is often a good practical choice in order to get good local service.

Serial: in the forms RS-485/488, RS-232/C (USB is a variant) and Zigbee (Mesh Serial signalling Networks).  Serial interfaces have a wide variety of physical interfaces (DIN 9, DIN 15, RJ Series 11/45, USB, Wireless channel interfaces) in the end the signalling protocol foundation is the same with some hardware vendors adding additional options to the class hardware contact/confirm, confirm again then send, then check to to see that the data arrived and send a T/F message to the sender from the receiver that it has arrived. Serial is definitely the lowest hardware cost and lowest bandwidth requirement but also requires more work to hook up at the software level to get the level of information required for monitoring and control working to even a basic level of usefulness by today’s standards. Still Serial is often the way to go for simple install and forget systems and easy interfacing to local and remote weather instrumentation and sensors.

Internet Protocol Suite: A way of communicating software packets of information created by applications running in a device with a cpu and memory  from   physical MAC “Machine Address Code” addressed Ethernet hardware (or other network communications hardware with their own address schemes) via software configured Network Transport software control payload schemes (frames) which are sent over physical wires or various wireless transmission schemes. This is largely the world our PCs, mobile phones and tablets live in today. Increasingly it is also the world our industrial devices are migrating  too to take advantage of the convergence of these displays and computers we work with and the software they run to make our industrial devices part of bigger systems and services which help us deliver more value to our customers at lower cost. So technology marches on now in the Industrial world  under the new Internet label of “Internet of Things”, IoT, to help connect everything to everything, first using IP V4 addresses translated through NAT Network Address Translation Gateways to work in bigger all encompassing networks in the IP V6 address space. The world is dominated by IP, which is the infrastructure on which the World Wide Web operates together with millions of servers and end devices.

OK, which one do I pick? Canbus, Serial or  Internet Protocol?

The answers is the dreaded “Will it depends…”,  on :

  • Which Controller you already own or plan to buy for your Solar Panel Generation charge and grid control?
    • Often other factors need to be included like;
      • the weather instrumentation used and what it supports
      • external sensors providing input to the overall system to allow control actions to occur

The external monitoring gear mentioned above is often not the biggest cost item and therefore these devices tend to use less expensive serial interfaces like RS232/C or or RS485/488, which are simpler. If the devices are on wireless however you could see such devices mke use of Zigbee mesh serial wireless modems, which are more expensive, however when the wiring distances are factored might be a better way to go if the alternative is long expensive cable runs for RS32/c over twisted pair RJ11 shielded cable at US 6 cents/ft.

  • How do you plan to remotely monitor and control your hybrid Wind/Solar Power Generation Facility?
    • If the answer is “Through my Andriod or iphone”, then you will most certainly use the Internet Protocol suite , or “IP” for short, to find your way to your controller, usually through your browser or some applet on your device using browser based http suite protocols to reach the mini web server which resides inside of your controller. Which means you will be buying a more up scale controller with a mini web server to facilitate such remote monitoring and control from anywhere. Such controllers then run the network gateway programs to local devices running lower cost Serial or Canbus interfaces to make it all work seamlessly without the need for you to program anything. These mid to upscale controllers are definitely packaged convenience which comes at a higher price than simple stripped down solar charge controllers, with more simplistic programming.

Regardless your choice for connecting Solar to Wind,  Wind will always be configured as the prime mover, which means Wind always gets first priority with the Solar controller, mainly because the output is quite variable and the wind charge controller is simple and low cost, which means the Solar controller needs to be smart enough to to decided what to do with the output given the current battery levels, the price offered by the utility and the current power needs behind the fence.

Overall your communications type selection is really about practically balancing connectivity, convenience, power generation and storage efficiency with cost to suit your budget and make sure you hit your Cost/W targets for your investment in a hybrid Wind/solar generation and storage facilities get the payback you need in in 5-7 years on an investment tat has a useful life of at least 15 years and if properly maintained 25 years.

In reality most Hybrid Solar/wind Power Generation Facilities use a Hybrid communications scheme between charge controllers, WAN gear, and local “PAN” Private Area Network instrumentation and sensors, so its always good to quaify electrical contractors in this regard before moving forward.


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