Thursday 29 August 2019

Solar power 4 years on...

Its been 4 years since I switched on the solar system, sadly about 1 week before the 4 year date the inverter went up in smoke..

My ROI is up in smoke with that because the forecast was that I will even up over 5 years. We are a year short, plus added to that I needed to replace the batteries about 6 months ago.

The question then is Solar power sustainable....?

Lets look at the Maths... (using average values to simplify it)

System cost R 42 626.93 ( this includes the new batteries)

The average usage per day before solar was 20.24 units so annually its 7386.76 units and at the time to cost of a unit was R 1.55 so prior to solar a years worth or power cost me R 11449.48

The average usage per day after solar was 15.89 units, so the same calculation means its 5800.90 units for the year at R 1.87 per unit means a total cost of R 10 847.69.

Now that does not look too great at first glance but we need to consider that the cost of power is a moving target.

To simplify it lets assume I had two identical houses one on solar and one on Grid.

The table looks something like this...yes... year 3 power cost more than year 4, I have the slips to prove that, not quite sure how that worked, it might have had something to do with Free basic units..

 UnitsYear 1Year 2Year 3Year 4Total
Grid House73861298513849142401386454937
Solar House58001019610875111821088743140
Power cost 1.761.881.931.88 

So the grid house has a power bill of almost 55K while the solar house has a bill of about 43K.

Not a lot in that, in fact take into account the initial investment of almost 43K and the estimated savings of 11K per 4 year cycle and you would be better off investing 43K into a savings account at 8% which would yield 13K over the 4 year period. (simplified)

BUT, we are not taking everything into account, what we can't measure is the exponential growth in power use, we have added things to make our lives easier, we ran a small air conditioner on the Solar system on hot days, we added appliances, computers and smart devices, all these use power and all this power is supplemented by the solar system in the day. So our demand is higher than the pre solar days.
ADD to this the convenience that when load shedding happens our power stays on, we are all willing to pay for this convenience.

So just exactly how do we then view Solar power from an ROI perspective? The ROI charts don't have a column for "cost of convenience".

I guess someone with a lot more knowledge can spin the numbers a little better and break it down into components so you have the things that last 25 years and the things that only last 4 years, crunch all those and it probably looks a lot better.

To me, I would do it purely for the convenience without giving it a second thought..



Thursday 18 July 2019

Home or Small business Firewall appliance



Fibre is everywhere, its reshaping our daily lives, I recall a few years ago when we were all stuck having to use ADSL, oversubscribed and erratic at the best of times. Nowdays we can stream TV in full HD while someone has a skype video call and someone else downloads emails. Its great…..I think… but is it really? 
Children nowdays all have tablets and one annoyance I find is that all the games have adverts and links, before long they have clicked or touched, and the Tablet is full of junk. In some instances, they have clicked and ended up in places where one would prefer they did not. 
Well, I found a great solution....
It’s a small Firewall Appliance, ordered off the shelf installed with the latest version of PFSense. This is a full firewall product that will give any commercial competitor a good run for its money, except that PFSense is open source. (Free)
These boxes are perfect for the job, they all can run the WAN DHCP configuration that most ISP's use and by default they allow nothing in but the LAN is allowed out. So a basic setup will get your home connected in no time.
The appliance I bought has 4 Ethernet ports for use, this is fantastic if you have a more than basic setup like I have. One port is LAN, one port is Fibre WAN, one port is LTE WAN and the other port is DMZ for guest Wifi.
You can run some pretty nice services that will for example strip those banner ads in YouTube and many websites. You can block sites based on DNS Blacklisting or category. (malware, Advertising, social media, Adult…)
If you really want to get fancy you can give priority to the Video calling but limit/block your teenagers ability to download torrents with the Traffic Shaper.
Of course, there is a web proxy you can use with its own antivirus engine and then you can use the DHCP function to control all your local addressing too.
I bought these boxes for 126 USD each, they ship with 2 Gigs or RAM and a 16 Gig SSD. They are low power devices and run super quiet as they are fan-less. You can specify more RAM and SSD if you wanted to.
My boxes arrived with PFSense installed but you could always install your own PFSense build directly off Netgate’s website.
The software is very capable, you can run two of these in a HA Cluster if you want and failover is within seconds, for any small to medium business that does not have the budget for Checkpoint this is a really great second choice. Sadly, it does not do any SD WAN although if you created multiple link and tuned the Traffic Shaper you would get pretty close.
A super little box for a bargain price...
Here are some pictures:
New in the box..


Tuesday 14 May 2019

Smart ET Remotes

Smart is for everyone:

Smart home is more and more becoming a phrase heard almost everywhere. It is sure to convenience us in some respects and if you are wary of letting it get too smart then just hold the reigns tight.

There are varying degrees of smart, best thing is to stick at the level that you are comfortable.

I will make some posts about smartening up your home, all are more or less DIY-able, you don't need to be a genius, just some tech savvy and common sense will do.

The devices I have used are:

4 Channel relay switch, this is a smart switch that can be used to switch or connect anything be it a 12v light, a 220v light, motor or a dry contact like a door buzzer. Its a bank of 1, 2, 4 relays that can be pulsed (latched) or switched on/off. This is what I am using to remote switch my modified ET Remote. I have also used this to wire up a watering system, the relays simply connect to the valves for each watering zone. (not that we can use it now)

Smart switch, this is a single 220v switch that you put in line with a light or appliance. The switch can be accessed via the smart phone app but you can also setup a scheduled timer on the app that will e.g turn on a light at 8 pm and off again at 8 am or switch on a pool pump for 2 hours every day or other day.

4 Channel Smart switch, this is the exact same thing as the above switch, just a bank of 4, this comes with DIN rail clips so it can be mounted din the DB. This only switches 220 volts.

30 Amp Smart Switch, once again this is the same as the single smart switch, just 30 Amps load capable, so you can stick it in line with you geyser. Useful for a timer function.

Smart light switch, these are glass panel light switches that work on touch. Its the exact same functions as the smart switches in that you can add a timer or schedule, the glass face is very nice looking. They come in a standard 2x4 size and a irritating 3x3 size. If you have a 4x4 light switch then you need to do a modification to a blanking plate to make it work.

There are a host of other units that will allow you to interface almost anything with a smart switch, all the units will allow you to turn devices on/off with Amazon Alexa or Goggle Home. The above few are the ones that I have personally installed, as I add more smart devices I will put them into the blog.

Firstly let me do the 4 Channel Relay with the ET Remote:

Now there are probably many ways to do this and I am sure there will be a stack of people with other advice, that's great. Below is what works for me..

I needed to be able to (1) open my gate from anywhere, (2) open the garage door from anywhere and (3) arm my remote from anywhere.
The alarm was easy since mine is already connected via a phone app but having a second option is always a good idea.
The Garage and gate are a small challenge since they don't have communication modules. Yes, I could run a wire to my alarm and create a zone that can be triggered by a code on the keypad, but that's too much trouble.

There is a simpler way, since the Gate, Garage and Alarm all work off the same 4 button ET remote so I am halfway there.

I bought a "smart relay switch" and added it to my home wifi, it comes with a phone app (eWeLink) that allows me to trigger each relay independently. I can configure the module for a "latching" mode, this means its not just on / off but rather like a quick pulse.

Here is a screen shot of the eWeLink application




I then took a ET Remote and opened it up, using some tech skills I cut off the 4 switches that make the buttons and replaced them with 2 wires to each switch, I soldered the wires to the connecting pads on the PC Board. These wires I then took into the smart relay. The relay then will act as the switch and "latch" the two wires together when I press the switch on the application.

End result is that from the Phone App I can then press whatever button I assigned to the ET remote button to perform that function. As long as my phone is connected a network be it 3G or WiFi the functions will work.

I put the remote in a central place in the house so any interference from outside is negated by the walls and roof.

Costs:
I already had an ET remote so I did not need that, all I needed was a smart switch. Best place to get the is China but since it takes too long we need to pay the local premium.

Communica is a good option, Netram is also an option but its about R 100.00 more.
Just for interest sake, you can pick these up for about 20 USD in China. Below is a one button option,  so if you wanted to wire up a single button remote then the is your device.


 

Here is a photo from the user manual..






















Here is the complete unit without the covers on.
















Here is a pic from the "hacked" remote.

















If your soldering sucks... I could be persuaded to do it for a bottle of red wine... if you need the whole solution it may take a case, if the case is given first, it may take a while to complete...


Thursday 10 January 2019

IT Infrastructure --- “least cost spending”


I have over the years found ways of doing things that cost very little or in some cases nothing. Yes there are downsides to “free” but its not always bad news.
Here is a list of things that can be done for a small company that will give you the feeling of a big solution.

Connectivity, we all need it and with the advent of fibre everywhere it’s a must have. How do you terminate your fibre to the home/business? The option of the cheap and nasty router is there but in the end its still just cheap and nasty.
I have found PFSense to be a fantastic solution, it’s a state-full firewall and can handle as much as you can throw at it. All you need is an old-ish PC with two network cards and you are good to go. It can do all the functions you would expect from an enterprise class firewall for the cost of ZERO.
If you wanted alternative hardware, you can buy one of those fan-less PC’s from China, they will cost you about 100 USD, comes with 2 LAN ports, a few USB and HDMI, it runs off onboard flash and runs PFSense perfectly.

If that is still not what you want then scrounge around few an old Riverbed appliance, re-flash it with PFSense, sadly it will only run the 32 bit version but it will run it very well.
PFSense can run in a HA configuration, so get two Riverbed Appliances and suddenly you have some redundancy, add a second link and you have an enterprise solution.
The firewall can do anything that an enterprise solution will do; site to site VPN, PPTP VPN, routing, policy routing, NAT, GEO IP blocking, proxy….. and more..
Yes, there are more free version around, I think they spilt off PFSense and created OpenSense at some point but since I was around from the initial stages of PFSense I have always just stuck with it. After all, if it works, why change it…

Monitoring, this is another essential requirement no matter how big or small your organization. A good monitoring system will be able to alert you of things as soon as they happen or in some cases before they happen. I use PRTG for all my monitoring requirements; the really great thing is that for a small organization you can get away with the “free” version. This is a full running version that is limited to 100 sensors. In a small business that is enough to monitor quite a lot of things.
You can monitor via SNMP and/or WMI which gives you insight into your connectivity devices and Windows servers. You can track things like disk space use get alerts generated long before the disk runs full.

Historical graphs can be viewed and netflows can be checked all giving you enough information to know what is happening on your servers, hosts and network.

Server Platform, in the past it was standard practice for a small company to have a glorified PC running the local copy of Pastel accounting or payroll, then someone had a PC that doubled up as a “ Data server”. Backups were problematic and in the end you had multiple copies of data all over the place. With the advent of VMware most corporates have moved off and gone the VMWare route leaving the smaller companies wondering what now?

Well, thankfully this has changed too, VMWare is available to the small business in the form of a “free” version.  (has actually been for a while already) It’s a working version of the platform with some limitations, but the limitations are all the things that a corporate would require.
For a small company the free version is a perfect platform to host the accounting or payroll system and any company data. The limitations are along the lines of clustering and HA.
…. Then there is the question of backups…. This is one of the limitations of the free version, if you wanted to use something like Backup Exec or Veeam you will be stopped short because the free version will not support it.
Having said that, there is a free version of Veeam but it will not run on the free VMWare, so you either need a licensed VMWare platform or a different product.

Backup software, and there just had to be one, there is a product called Unitrends that has an appliance that worked perfectly with the Free VMWare.
Of course it’s a “free” version of Unitrends too and the limitation is 2 TB of backup data. Most small companies do not backup more than a few hundred megabytes per night. The software runs as a VM on your VMWare platform, it will send you reports based on your settings, restores are quick and painless, it support files based restores or bare metal restores. You can do a backup to NAS or local disk or you can backup to local disk and do a replicate to NAS.

Wifi, we all need managed wifi connectivity and there is no other option for corporate or small business as far as I can see. Ubiquity have a fantastic selection of products, their Unify solution is great. The Access points come in 2.4 / 5 GHz models but the best thing is, free from their website is the Unify controller that will tie all the access points together. You can create a closed network and a guest network, limit use and access and have full visibility of it, all for the cost of the Access points. The controller can run as a small VMWare appliance as a linux machine meaning you don't need a Windows licence for the host.

There are a host of IT things that you can get for free, having a VMWare platform means its even easier to spin up a Linux appliance to run something, the possibilities are endless, you just need some inspiration....