EnergyChaser, LLC

If you’re a property manager, landlord, or tenant in a multi-unit building, you’ve probably wondered how utility costs get divided fairly among residents. At EnergyChaser, we believe in complete transparency when it comes to utility billing. In this post, we’ll walk you through exactly how we calculate tenant invoices using a straightforward, fair pass-through rate model.

The Three-Step Process

Step 1: Start with the Master Meter Invoice

Everything begins with the actual utility invoice for your building’s master meter. This is the total amount the utility company charges the building, including all taxes, fees, and charges.

Example: Let’s say your building receives an electrical invoice for $10,000 for the billing period, and the total consumption was 40,000 kWh.

Step 2: Calculate the True Cost Per kWh

Next, we calculate the actual cost per kilowatt-hour (kWh) by dividing the total invoice amount by the total building consumption.

Formula: Rate = Total Invoice ÷ Total Consumption

Example: $10,000 ÷ 40,000 kWh = $0.25/kWh

This rate includes everything – not just the base energy cost, but also delivery charges, taxes, and fees. This ensures that the full cost of electricity is accurately reflected in what tenants pay.

Step 3: Apply the Rate to Individual Tenant Usage

Each tenant unit has a submeter that measures only their specific electricity consumption. We multiply each tenant’s actual metered usage by the calculated rate to determine their invoice.

Formula: Tenant Invoice = Tenant kWh × Rate

Example: If a tenant used 400 kWh during the period: 400 kWh × $0.25/kWh = $100

What About Common Areas?

You might be wondering: “Do tenant meters capture all the electricity used in the building?” The answer is no, and that’s completely normal.

In our example above, if the building has 70 units and each tenant used 400 kWh, that’s only 28,000 kWh total. But remember, the building consumed 40,000 kWh according to the utility invoice. Where did the other 12,000 kWh go?

This difference represents common area and building system consumption that tenants don’t directly control:

• Hallway and exterior lighting
• Elevators
• Laundry rooms
• HVAC systems for common areas
• Parking garage lighting
• Security systems
• Other building equipment

With EnergyChaser’s model, the landlord covers these common area costs as part of building operations. In our example, that’s 12,000 kWh × $0.25/kWh = $3,000 that the property owner pays.

Why This Approach is Fair

For Tenants:

• You pay only for what you actually use
• The rate reflects the true, all-in cost of electricity
• Your submeter provides accurate, individualized tracking
• You have control over your electricity costs through conservation

For Property Managers and Landlords:

• Complete cost recovery for tenant-consumed electricity
• Transparent, defensible billing method
• Reduced billing disputes
• Simplified utility management
• Clear separation between tenant and common area costs

The Math Always Works:

• Tenants collectively pay: $7,000 (28,000 kWh × $0.25)
• Landlord pays: $3,000 (12,000 kWh × $0.25)
• Total: $10,000 ?

No Markup, No Guesswork

Unlike estimated billing methods or ratio utility billing systems (RUBS), EnergyChaser’s approach eliminates guesswork. There are no arbitrary allocations based on square footage or number of bedrooms. Instead, you get:

• Actual consumption data from submeters
• Actual utility rates from real invoices
• Proportional cost sharing based on usage

This is utility billing at its most transparent and equitable.

Ready to Simplify Your Utility Billing?

Whether you’re managing a small apartment building or a large multi-unit complex, EnergyChaser makes utility billing straightforward, fair, and fully transparent. Our automated system handles the calculations, generates invoices, and provides detailed reporting for both property managers and tenants.

At EnergyChaser, we don’t have a formal metering specification document for utility meters. Meters are often VERY location specific as I will explain below. Also, we are typically called after the meters (water, electric, other) are already installed and tasked with doing data collection. This is not the optimal way and often makes metering projects more expensive and complex.

EnergyChaser only does remote automated meter reading (AMR). We do this in many situations with existing metering equipment if technically possible and feasible. Although we do have a web interface to do manual reads, we typically only perform automated remote reads.

Meters of all types that are ‘remotely readable’ or ‘cloud based’ tend to be very expensive proprietary solutions that often use technologies like cellular or satellite. These are only cost effective in specialized remote/rural locations with one or very few meters that don’t have a LAN/WAN available with Internet.  This is not the case in typical applications in urban locations.

What EnergyChaser does:

We read all meters in all our customer sites every five minutes. We also automatically monitor the entire metering system to ensure meters are online at all times to minimize data loss. We read all connected meters even if there is not a tenant assigned or the meter is on a spare feeder. Our monthly reports flag instances where a space or feeder has unassigned (no tenant) usage.

The reports/bills/invoices can be as complex as is required. By default, our tenant invoices contain graphs of their utility usage. We find that if we provide detailed information to the tenants, there are rarely any questions asking ‘Why is my bill so high?’. This information also helps the tenants reduce their own usage.

Besides the data collection and system monitoring and because we have detailed 5-miniute interval data, we also occasionally produce reports for tenants like LADBS reports and answering customer/tenant operational questions like when a tenant questions their bill.

BTU Meters:

I am going to discuss BTU meters first because the recommended solution is simpler and more straight forward than the others. We recommend the System-10 meter from Onicon: https://www.onicon.com/products/system-10-btu-meter/

There are few choices in the BTU meter field and we have had very good luck with these meters in the past. They are very flexible, reliable, and can be configured for any pipe size. We use a budget a price of ~$7k installed with all required components/accessories. Chilled water BTU meters are expensive to install because they require a plumber and you often need to cut into water filled pipes.

The meter MUST be ordered with the correct options and factory configuration. Once the properly ordered meter is installed and powered up, all that is required is an Ethernet connection to your LAN/WAN and we are ready to start collecting metering data.

If you are installing many BTU meters in one geographic location (food court) with a pipe size under 2.5”, there may be lower cost options. Call to discuss the limitations.

Domestic Water Meters:

Domestic Water meters are actually two components in one: the lower meter section (normally brass) that actually measures the water usage and is sized based on pipe size AND the METER REGISTER mounted on top that typically has the dials for local meter reading.

We are only concerned with the meter register and its features. The register must have a wired pulse output. There are other methods but it has been our experience that this makes things simple, low cost, and does not lock you into a proprietary solution.

We then supply an electronic device (~$600 fully configured/delivered, less if ordered in bulk) near the meter that counts the pulses and is connected to your LAN/WAN for data collection.

Some examples of these types of registers that we have used are the Badger HR-LCD PULSE and the Neptune Tricon S. We don’t care about the water meter type or size underneath as long as it has a compatible register installed.

Electric Metering

Electric metering has the most options and choices off all three types of meters.

The final metering choice depends on the following parameters:

1. Geography: How many meters will be required in one geographic location/electric room in the facility? This effects your choice because of multipoint type meter options available today and this is the lowest cost solution per metering point. This is both from a purchase and installation point of view.
2. Meter parameters required: Most often for tenant invoicing, you only require kWh. However, sometimes you may need to look at, or invoice based on, Power Factor and this requires more meter parameters that not all meters provide. What about voltage/amp monitoring?
3. Communication options: Is there a LAN/WAN network connection close by? What about WIFI? Basically, how are we going to get the meter readings from the meter to the LAN/WAN network for data collection?
4. Feeder size in amps and voltage level. Anything over the 480V level gets more expensive and complex to install.

We current interface with Eaton, GE/Multilin, and E-Mon-D-Mon branded meters.

Summary

Selecting water and BTU meters is easier but are often installed in the tenant spaces so the installation is more administratively complex. Electric meters are often installed in central locations like electrical rooms so the installation is administratively simpler but often more disruptive because the installation often requires multi-tenant or complete electrical shutdowns. Electric metering choices are also more complex.

EnergyChaser can provide inexpensive on-site or remote consulting services to help make the best selections for each type of meter for a specific site. Call us for more information.

724-799-1529

I was looking for a way to make a Raspberry Pi into a VPN Gateway for my home network.

This solution started with this page: https://gist.github.com/superjamie/ac55b6d2c080582a3e64

Change /etc/network/interfaces to suit your networking configuration:
auto lo
iface lo inet loopback

auto eth0
allow-hotplug eth0
iface eth0 inet static
address 192.168.1.2
netmask 255.255.255.0
gateway 192.168.1.1
dns-nameservers 8.8.8.8 8.8.4.4

Then SSH in and install a VPN client. I use OpenConnect: http://www.infradead.org/openconnect/

root#: apt-get install openconnect

Setup Routing and NAT

Enable IP Forwarding:

echo -e '\n#Enable IP Routing\nnet.ipv4.ip_forward = 1' | sudo tee -a /etc/sysctl.conf
sudo sysctl -p

Setup NAT fron the local LAN down the VPN tunnel:

sudo iptables -t nat -A POSTROUTING -o tun0 -j MASQUERADE
sudo iptables -A FORWARD -i tun0 -o eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i eth0 -o tun0 -j ACCEPT

Make the NAT rules persistent across reboot:

sudo apt-get install iptables-persistent

The installer will ask if you want to save current rules, select Yes

If you don’t select yes, that’s fine, you can save the rules later with sudo netfilter-persistent save

Make the rules apply at startup:

sudo systemctl enable netfilter-persistent

Older system (Wheezy) may need: sudo dpkg-reconfigure iptables-persistent

Configure Other Systems on the LAN

Now we’re ready to tell other systems to send their traffic through the Raspberry Pi.

Configure other systems’ network so they are like:

• Default Gateway: Pi’s static IP address (eg: 192.168.1.2)
• DNS: Something public like Google DNS (8.8.8.8 and 8.8.4.4)

Don’t use your existing internet router (eg: 192.168.1.1) as DNS, or your DNS queries will be visible to your ISP and hence may be visible to organizations who wish to see your internet traffic.