Guide for Octopus users
Octopus Energy is the UK's most innovative energy supplier, with a lot of great options which allow engaged customers to save money and reduce climate change. All these options can be a lot to get your head around, so I decided to write this guide for new Octopus users, of the things that I believe new users might want to know. At the time of writing this guide I wasn't an Octopus employee, just a very happy customer. I may have made mistakes, especially about components that I haven't used, so please check if anything I've written seems wrong. This was written in August 2020, so some things may be slightly out of date by the time you read them (although I will try to update it where needed).
Contents
- Getting started
- Octopus tariffs
- Getting your account details
- Tools for managing your data
- Consumption data
- Price data
- Octopus bills
- When problems occur
- Frequently asked questions
- Advanced information
- Glossary
Getting Started
This guide is aimed at Octopus customers with smart meters. Even if you're not an Octopus customer or don't have a smart meter, you can still read it, to as a guide to what you can expect once you are.
If you are not yet an Octopus customer and want to become one, you can sign up using this link - that way you and I each save £50.
If you are an Octopus customer but don't have a smart meter, you will need Octopus to get one installed. There is quite a backlog of requests to install smart meters in many parts of the country, not helped by the Covid lockdown, so unfortunately you might find yourself waiting a while. It is worth ringing Octopus occasionally to check up on the progress.
Octopus can only get data from certain models of SMETS1 smart meter (eg the Secure Liberty 100). If you have a SMETS1 meter that they cannot read, you will most likely need to wait until it has been adopted by the DCC, at which point Octopus will be able to get its data from the DCC along with all the SMETS2 meters. This should be taking place over the next year.
Octopus Tariffs
Electricity Consumption
The flagship product for engaged electricity customers is Agile, which sets a difference price for each half hour, reflecting wholesale market prices, with an extra high price from 4-7pm local time. Every day at 3:45pm, a market auction is held for each half hour from 11pm that night until 11pm the following night. Octopus use the results of this auction to calculate the retail prices, publishing it soon after 4pm (occasionally it is delayed - see the section on prices below). The formula used depends slightly on which region you are in, for example, in London they multiply the wholesale price by 2, and then add 12p/kWh for any consumption from 4-7pm local time, before finally adding 5% VAT. There is a cap of 35p/kWh. Sometimes the wholesale is negative, in which case you will be paid for consuming! Unfortunately, day ahead wholesale prices have risen a lot in 2021, and most customers will find other tariffs better value at the moment.
Octopus has another innovative product called Go, aimed at EV owners. This gives the customer 4 hours (from 00:30-4:30) at a cost of 5p/kWh, and the rest of the day at a higher price which depends on the region. They have since released a range of variants of this, called Go Faster, allowing customers to choose between 3 and 6 cheap hours, and allowing them to choose for the cheap rate to start at different times. You can see more details of these on this page
Octopus do offer standard tariffs, with a single known price for all hours of the day. These come in a fixed variety (FIX-12M-20-02-12, or Octopus 12M Fixed), where the price is fixed for a year, and a variable variety (VAR-19-04-12, or Flexible Octopus April 2019 v1), where it may change at 30 days notice. Note that none of Octopus's tariffs have exit fees, so you are free to start off on Fixed and then switch to another tariff or even leave Octopus.
If you have an economy 7 meter, which distinguishes between day usage and night usage, most of the standard tariffs (includin FIX-12M-20-02-12 and VAR-19-04-12) do have economy 7 tariffs. These will typically allocate any electricity you use between midnight and 7am local time to the cheaper night tariff. However, on occasion the smart meter can be out, so it is worth keeping an eye on how much consumption is allocated to each tariff.
The final product I will mention for electricty consumption is called Tracker. This was a precursor to Agile, but I believe it is still available on request. There is a single price for each day, and it is set on the previous day based on the 11am day ahead auctions. This product has the advantage that it doesn't require you to have a smart meter. However if they don't use your smart meter data, it means that it won't take into account any savings you may hope to make by shifting volume from one day to another.
Deciding which product to choose isn't easy. If you don't have a smart meter, you're likely to have to stick to one of the standard tariffs. If you do have a smart meter, consider the following points:
- If you have flexibility in when you use power, and you can mostly avoid using it from 4-7pm, then Agile will probably save you money. Be aware it is more complicated, and will require buy-in from the whole family, but there are large savings to be had if you use it well.
- If you use a lot of power in the early hours of the morning, say charging an EV, but you use a lot of power from 4-7pm, eg cooking dinner for the children, then GO may makes most sense.
- If you use a lot of power from 4-7pm, and not much in the early hours of the morning, and you can't easily shift usage to cheaper times, then probably stick with one of the standard tariffs.
- If you have solar panels or a battery, this might change when you are likely to import power from the grid, and which is the best tariff.
You can easily change between tariffs, so it may make most sense to occasionally take a look at your usage to see if another tariff would have been cheaper. However, keep in mind that just because one product has been cheaper in the past, it may not be cheaper in the future. For example, Agile and Tracker will be cheaper in summer than winter.
Electricity Export
If you have solar panels that produce power that you can't use, and are not receiving feed-in tariff payments for your production, Octopus will pay you the power that you export to the grid. (I believe you can still get it if you are receiving feed-in tariff, but you will lose the deemed export component.) There are three main tariffs for export power.
The fixed tariff (OUTGOING-FIX-12M-19-05-13) pays 5.5p/kWh for any electricity exported. You can't have this tariff alongside Go or Go Faster.
Octopus also have a half-hourly varying tariff, AGILE-OUTGOING-19-05-13. This tariff is similar to the AGILE tariff for purchasing electricity, being based off the same half hourly wholesale prices, however the formula is different, producing export prices that are about half the import prices. There is no cap on the prices, but the prices are set so they never go negative (but may occasionally be zero). You can't have this tariff alongside Go or Go Faster.
Octopus SEG (OUTGOING-SEG-FIX-12M-20-07-07) pays 3p/kWh. It is the only outgoing tariff that can be used alongside Go or Go Faster.
The decision of which is best is likely to depend on how much you are able to export after 4pm, as the AGILE OUTGOING price after 4pm is significantly higher than 5.5p, while before 4pm it is usually lower.
Gas Consumption
Each of Octopus's standard tariffs offer a gas tariff. Like with electricity, there is a 12 month fixed contract (FIX-12M-20-02-12) or a variable tariff (VAR-19-04-12). There is no exit fee on the fixed contract. Note that you can be on a different tariff for your gas and electricity consumption.
As well, Octopus offer a gas Tracker product. With this product, you are charged a different price each day, based on the wholesale day ahead gas price. For example, in London, the tracker price is equal to the wholesale gas price (converted to p/kWh), multipled by 1.06, and you add 1.3, and then add 5% VAT. It is worth being aware that Octopus sometimes base your bill off modelled daily consumption (based off your monthly consumption) rather than your actual daily consumption. In practice this doesn't tend to make much difference, as the gas prices don't vary from day to day as much as electricity prices. This product is less well known, and you will have to request it (make sure you tell them you want to stay on your existing electricity tariff, otherwise they will switch you onto Electricity Tracker as well).
Gas Tracker will probably work out a bit cheaper than a fixed tariff unless you're only using gas for heater in Winter, but there's probably less of a saving than there is in switching from a fixed electricity tariff to Agile.
Getting your account details
The most important account detail is your account number - this is a string like A-ABCD1234. You can find it at the top of your bill. You can also find it by logging into the Octopus website, and going to the dashboard, you should then find it in the URL.
The next detail is your API security key, which takes the form sk_live_asdfasdfasfasdfasdf. You can survive without knowing this, but there are a lot of useful features that I will mention that rely on knowing it. If you go to the developer dashboard, it will show you your security key. This key is like a password, so don't post it any forums, and if you are worried about someone knowing it, you can generate a new one on the developer dashboard.
Next, for each of your accounts (electricity consumption, gas consumption, electricity export) you will have:
- MPAN (or MPRN in the case of gas) - eg 1200000000000 - the first two digits indicate your region
- meter serial number - eg 13C9025021
- product - eg AGILE-18-02-21
- tariff - eg E-1R-AGILE-18-02-21-C. The first character indicates electricity or gas. You will have 1R next, unless you are on an eco7 tariff. It then has your product, and finally a letter indicating your region.
You can find some of these details on the developer dashboard, but occasionally it gets it wrong. You can also go to my Smart Meter Data Viewer wesbsite, for which you will need to enter your account number and security key.
The most complete source of account detail information is to go to the generic API website. Replace A-ABCD1234 with your own account number, and include your security key. This will show you your full history of mpans, meters and tariffs.
I mentioned above that both the first two digits of your MPAN, and the last letter of your tariff, tell you the region you are in. The full listing of regions is:
| Region | MPAN Number | Region Name |
|---|---|---|
| A | 10 | Eastern England |
| B | 11 | East Midlands |
| C | 12 | London |
| D | 13 | Merseyside and Northern Wales |
| E | 14 | West Midlands |
| F | 15 | North Eastern England |
| G | 16 | North Western England |
| H | 20 | Southern England |
| J | 19 | South Eastern England |
| K | 21 | Southern Wales |
| L | 22 | South Western England |
| M | 23 | Yorkshire |
| N | 18 | Southern Scotland |
| P | 17 | Northern Scotland |
Tools for managing your data
In-home Display (IHD)
When you got your smart meter, you should have received a little device with a screen, that shows you how much electricity and gas you are using. Some models of in-home display work much better than others. In particular, most models (other than Hildebrand's) are unable to reflect Agile prices, and instead show a fixed price.
One significant advantage of the IHDs is that they are able to show you real-time consumption, while most of the other tools are only able to show you at best the previous day's consumption or export.
Octopus website / bills
The Octopus website shows you the current day and next day of Agile prices, and all of the historic consumption that they have collected from your meter (usually up to 1-2 days ago). You can also see all your historic bills. It is a good reliable source, but it doesn't have all the information you might want, and lacks things like the ability to export data to Excel.
The Octopus bills are in pdf format, and contain a lot of detail. For example, if you are on Agile, there will be a page for every day, with a row for every half hour showing your consumption/export and the the price for that half hour. They are a useful final reference, but they aren't that helpful if you are trying to make sense of your usage. Octopus bills are sometimes delayed as they can't be issued for Agile / Go until they have all the half hours of data. As a result you may be unable ot see bills covering the most recent months.
Smart Meter Data Viewer website
I have built a website (https://energy.guylipman.com/sm/admin?source=octopus) that allows customers to load their data from Octopus and view usage, costs and emissions going back (back to January 2019 if you had an Octopus smart meter that long); calculate bills; and save data to csv to open it in Excel. You can also compare what your usage would have cost under different tariffs. You can see electricity and gas consumption, and electricity export data.
Octopus Watch
If you have an iPhone / iPad / Apple Watch, or an Android device, you can buy this app for £1.99 from the App Store or Google Play. This app is aimed mostly at Agile electricity customers, and shows Agile prices and historic electricity consumption and costs. It allows you to see the cheapest upcoming times, and to set alerts so that you can remember to turn on the washing machine, etc. It lets you export 3 months of historic data to csv. As well as the basic app (which works well on its own), you can buy a subscription for £0.99 a month (£7.99 for a year) which includes carbon intensity, electricity price forecasts to 48 hours, and consumption analysis. It will still show you your consumption if you aren't on Agile, but the prices and costs won't be right.
Octopus Energy Watchdog
Octopus Energy Watchdog is another good app, although only available for iPhone / iPad. You can buy it for £0.99 from the App Store This app allows you to see Agile prices, a month of historic electricity consumption and cost, and a month of gas consumption. You can also export historic data to csv to look at in Excel.
Bright App
If you have a Hildebrand in-house display or monitoring device, you may be able to see your consumption in the Bright app, available for free in the App store or in Google Play. These apps are able to show real time and same day consumption as well as historic consumption.
If you have a SMETS2 meter or a SMETS1 meter that has been adopted by the DCC, you can authorise Hildebrand to access you data from the DCC, allowing previous day's data to be visible in the Bright app.
Consumption data
The first thing to note is that Octopus don't receive your smart meter data in real time. My experience is that SMETS1 data is usually available around 8am the following day, but there can be delays. SMETS2 data usually takes up to a day longer to be available.
However, Octopus do experience lots of issues receiving that data reliably. Some issues are widespread, affecting most customers. Other issues will be specific to one model of smart meter, or indeed a small number of smart meters. In extreme cases they may need to send out an engineer to look at it.
Your smart meter stores 13 months of half hourly data (they are only required to store 3 months of export data). Even if Octopus are unable to retrieve your data for weeks and weeks, it is highly highly likely that they will eventually get it. So, try not to worry that the data will have been lost.
It is still worth chasing up missing data, as Octopus can't bill you for Agile or Go without having your full set of half hourly data. If I am missing data from more than a week ago, I email them on smart@octopus.energy, and they are usually pretty good at addressing it within a few days.
When looking at missing data, I look at two things: when is the last half hour for which I have data? And do I have gaps in my data? I have a website which answers these for any customer: https://www.guylipman.com/octopus/missing_data_check.html?account=A-ABCD1234&key=sk_live_BXmPhasdfvosRsdfm (use your own account number and security key - see above if you're not sure how).
The other place to see your data (and work out what is msising) is on the Octopus website. On your dashboard, there should be a link to View Smart Meter Consumption (and possibly for gas and export too). This takes you to the latest day of readings they have. It lets you scroll between days (though it won't let you scroll to a date that is missing data), or you can adjust the date in the website URL.
If you are regularly having difficulties getting your consumption data from Octopus, you may be able to get your data more reliably from Hildebrand or n3rgy, two providers who have developed alternative avenues to get data from a smart meter. However, if Octopus's difficulty reflects a fundamental problem with your smart meter, these other avenues may suffer the same issue.
If you have gas, your meter measures your consumption in cubic metres (m3), however you are charged in kWh. There is a conversion between them, but it varies a bit over time. If you have a SMETS1 meter, Octopus will get your quantities in kwh, however it may adjust it when billing. If you have a SMETS2 meter, Octopus will get your quantities in cubic meters, and will convert. Each bill should show the conversion that has been applied. However, there may be a small discrepancy between the kWh consumption reported by your smart meter and that shown on your bill. If you have a SMETS2 meter and use an app like Octopus Watch, you may need to input the appropriate conversion (usually around 11kWh/m3).
Price data
Agile Prices
The Agile consumption and Agile export prices are based on the day ahead half hourly auction on EEX. The results of this auction are typically published at 3:45pm UK local time, and cover each half hour from 11pm that night, to 11pm the following night. It typically takes about 15 minutes for Octopus to apply their formulas and publish retail prices for each region. As soon as Octopus publish them, you can see them on the Octopus dashboard. You can also see the prices soon after on the Energy Stats website, on Octopus Watch / Octopus Energy Watchdog, or on twitter on @energystatsuk.
Occasionally the Agile prices will be delayed in being published, sometimes to as late as 8pm. If that happens, don't panic, they will eventually be published (even if manually). I do have a workaround, which is a webpage that applies the Octopus formulas to the EEX prices (you can modify the URL for your region). Occasionally the cause of the delay is also prevents EEX showing their auction results, in which case this website will revert to estimates based on the 11am hourly auction.
If you are trying to do historical analysis on Agile prices, I'd recommend looking at the Energy Stats website. It has a lot of data in Agile and Agile Outgoing prices, and lets you download the price data going all the way back to 2018 to do your own analysis.
I have compiled all the fomulas for Agile by region on a separate page.
Tracker Prices
You can get the current and historical gas tracker prices on this webpage. You can get the current and historical electricity tracker prices on this webpage.
I have compiled formulas for each region and links to source data on a separate page.
Other tariffs
If you are on a tariff other than Agile or Tracker, you should be able to see the prices applicable to you on your dashboard or on your latest bill.
Octopus billing
The billing is my biggest complaint with Octopus (along with delays in getting consumption data, but that is largely out of Octopus's control). Some of the billing issues are a result of having products that depend on half hourly consumption, which can lead to delays in issuing bills if they are missing some data. But some issues could certainly be improved. It isn't enough of an issue for me to switch to a simpler product that would have fewer issues, but I will mention these issues to hopefully make things easier for other customers.
Part of the confusion is that each bill has multiple dates identifying it. When you go to "My Bills", each bill is shown with a start month and end month. These months may or may not correspond to the dates that the bills cover. When you go inside the bill, it has a date range at the top, and then a date range for each of electricity and gas consumption and electricity export. These dates may not align. It is incredibly hard, if you want to work out how much you've paid for electricity and gas over the last year, to work it out.
I would recommend looking at each of electricity, gas and export separately, and focus on the dates listed for each fuel. Octopus have recently introduced a balance history page, which helps a bit with this.
I have built functionality on the Smart Meter Data Viewer to calculate what your bills should be between two different dates. It doesn't bother with trying to match Octopus's rounding, but it should get close enough to at least give you confidence that you're not being charged too much.
Agile Bills
If you are on Agile (consumption or export), your bill for consumption (and/or export) will cover a whole number of days, and will include a detailed page for each day, showig half hourly volumes and price. A few notes on this:
- Consumption is rounded to 2 decimal places before being multiplied by the price (excluding VAT). Rounding is done using unbiased rounding, that is, 5 will round up or down, to whichever digit is even.
- Half hourly costs are then rounded to the nearest 0.01p.
- Consumption for each half hour, and cost for each half hour, are summed across each day, and across the full billing period. For each day and overall they also report the average price in p/kwh.
- If the billing period spans a daylight savings change, it gets really weird. The bill correctly covers a whole number of days in local time. But the days are split into days based on the timezone at the start of the billing period. As a result, each page will be 48 periods, and either the last page will have 46 periods, or there will be an extra page with the extra 2 periods. It doesn't make sense, and it is a nightmare to reconcile, but it produces the correct overall number.
- Standing charges (excluding VAT) are then applied for each day in the billing period.
- 5% VAT is calculated at the end of the process.
Gas Bills
You may have discrepancies in your gas bill due to variation in the conversion factor from cubic meters to kWh. Your bill should show you the conversion that Octopus has applied.
Gas Tracker Bills
If you are on the Gas Tracker tariff, your bill will have a row for each day, showing the consumption and price.
If they have your daily or half hourly meter readings, this may reflect your actual daily usage. If not, they may have taken your total usage for the month, and used a model to estimate how much you used each day. You can tell which they have done by seeing how much the consumption varies from day to day - if it varies smoothly, they have most likely used modelled consumption. In reality, this doesn't matter much as the gas price doesn't change much from day to day.
The bills also have a column showing the wholesale price. This value is wrong (out by a factor of 10 if I recall correctly) but this doesn't affect the final price or your cost.
Direct Debits
Octopus require customers to set up a direct debit. This means that even if there are sometimes delays in billing you, once the bill comes in you shouldn't end up with too much money owing.
Octopus let you change your direct debit amount (and may even suggest you reduce it if they think you are paying in too much). You can change the direct debit amount on the account page. You can also ask them to refund you some of a credit balance, although they might not do this if they haven't been able to generate a bill for the past few months due to missing data.
It is worth remembering that Agile bills will tend to be even lower in summer than you are used to, but will rise in winter. As a result, some people like to keep their direct debit slightly higher in summer, to reduce the increase in winter.
When problems occur
Octopus is a great company with passionate and knowledgeable people and innovative products, but things do go wrong sometimes, and issues can fall through the cracks. You sometimes have to be proactive in getting an issue sorted.
In the first instance, if I have a problem related to my consumption or billing, I recommend emailing smart@octopus.energy - this ensures your message goes to someone who knows about Agile and smart meters, though it can take a few more days to be looked at. Alternatively, you can call them on their support number 0808 164 1088, or you can message them on Facebook Messenger or send a direct message on twitter on @octopus_energy.
Sometimes these channels don't get any response, or you get responses that make it clear that the person assigned to help you doesn't know how to (admittedly, we are often calling about new products that not all their employees know about). If you don't get any response in a few days (give it a bit longer if it is smart@octopus.energy), or you are getting responses but it is clear that the person isn't able to help, it is worth escalating. You can try a different channel. If you are on Agile or Go, you can try escalating it to Phil Steele, who looks after products like Agile. Or you can email Greg Jackson, the CEO, on greg@octopus.energy, and he or one of his team will look into it and make sure the right person gets involved.
Sometimes even when you get the best person involved, there isn't much they can do. For example, if there is a problem with your smart meter, Octopus may not be able to resolve it themselves, or it may take months to resolve. It is up to you whether you move onto a standard tariff that doesn't depend on your smart meter, or be patient. It is frustrating when this happens, but it is unlikely that you would be in a much better situation with another supplier.
Another way of resolving issues with Octopus is on one of their customer forums. There is a facebook group Octopus Agile Chat with lots of helpful customers, and a Octopus Agile Forum, where lots of people discuss all sorts of questions, issues and solutions.
Other frequently asked questions
How can I save money on Agile?
The easiest way to save money on Agile is to avoid running the dishwasher / washing machine / EV charging / Power Shower from 4-7pm local time when prices are much higher.
The next tip is to be aware of the things you do that use a lot of electricity, that you can be flexible with - again, dishwasher, washing machine, EV charging, electric hot water heatig, electric baking. If it is something you use every day, you can look at setting up a smart timer so that it always runs at the cheapest times. If you run it less often, you can look at the prices over the next 24 hours and pick when is cheapest. Often there are cheap prices between 1 and 4pm, when you can run the washing machine more cheaply than you would at other times.
Sometimes you will want to decide whether to use electricity today, or later in the week, say for charging an EV ahead of the weekend. It can be useful to look at price prediction services. Predictions are quite unreliable, especially as you go more than 48 hours out, but at least they will take into account if it is expected to be windy in a few days time. The subscription version of Octopus Watch (discussed above) gives predictions out to 48 hours. I also have a webpage that gives predictions for the next 7 days (specify your region in the URL).
If you have solar PV, an electric vehicle, or a battery, there are a lot of clever things to do that are beyond the scope of this guide. You will find a lot of helpful suggestions on the 'Agile Chat' Facebook group or the 'Octopus Agile Forum' mentioned above.
Just because you are on Agile, don't neglect the boring ways to save on your energy bills, by improving insulation and not heating your flat when you aren't home.
Finally, you can save money by recommending people to join Octopus. If you go to the dashboard on the Octopus website, it will give you a unique code. If people sign up with this code you will receive a £50 credit to your account, as will they.
How does daylight savings work on Octopus
Timezones and electricity is a bit confusing - here is a summary of different ways that it affects you:
- You are billed for a whole number of local days, each from midnight to midnight local time. (This isn't well reflected in the bills - see the note on billing in the section above.)
- For Agile customers, every day soon after 4pm local time, the prices from 11pm that night until 11pm the following night will published.
- Also for Agile customers, the high price period runs from 4-7pm local time.
- Go customers get their low price from 00:30-04:30 local time.
- For economy7 customers, your cheap nighttime rate should be from midnight until 7am local time. However, this can depend on how your meter is configured.
- When Octopus retrieve your consumption, the last half hour they get is often UTC. This can lead to SMETS2 meters only pulling in until 23:30 in summer.
- Most of the apps display all times in local time, as does the Octopus website. They will show one long day (the last Sunday in October) and one short day (the last Sunday in March).
Advanced Information
Octopus benefits from a powerful API, that lets you retrieve consumption and price data. I have written a guide to the API which you might find useful.
The other great feature of Octopus is its community of technically minded customers that have spent time building apps, dashboards, analysis and interfaces with other technologies (see this article for some examples). If you are looking to do something similar, why not join the Octopus Agile Forum, where you will find the forum, where you will find people who are happy to answer questions and point you in the right direction or help you test what you've built.
Glossary
There are quite a few terms that get used a lot when dealing with smart meter data. I've tried to list the main terms that I have heard a lot, or which I have mentioned above.
Agile is the Octopus Energy's innovative product that has a different price every half hour, incentivising customers to use power when there is most spare capacity, helping the grid and the planet.
API - Application Programming Interface - this is a way that companies like Octopus can give customers and developers access to data. For more information about the Octopus API, visit this guide.
csv - a file format containing comma separated variables, which can be opened in Excel or Google Sheets.
DCC - Data Collection Company - this is an organisation set up by the government, who allow utilities and other authorised parties to access your smart meter data if you are on SMETS2. For more details visit their website.
Economy7 (or Eco7) - this is a meter that splits between consumption in the cheap 7 hours (often midnight to 7am) and consumption the rest of the day. It can also refer to a tariff that customers with these meters can use.
EV - electric vehicle, typically one that can be charged from the grid.
Go is an Ocotpus tariff that gives customers 4 hours of electricity for 5p/kWh each night, which may suit you if you want to charge your electric vehicle overnight but don't want the uncertainty of Agile.
IHD/CAD - In-home display / Consumer Access Device - these are different terms for devices used by customers to access their smart meter data.
kwh (and other units)The amount of electricity or gas a customer buys is typically measured in kWh. This is equivalent to 1000 Watts consumed over 1 hour (or 3600 Joules). The retail price of electricity is typically about 15p/kWh. Wholesale electricity is typically measured in MWh (= 1000kWh). Wholesale gas is often measured in therms (1 therm = 29.3071kWh). Gas meters measure gas in cubic meters (m3) - there is typically about 11kWh per m3, but this varies over time and geographically.
OFGEM - The Office for Gas and Electricity Markets - this is the UK's regulator for energy suppliers and wholesale and retail markets. It works closely with the Department of Business, Energy and Industrial Strategy (BEIS).
Smart meter / SMETS1 / SMETS2 - this is any meter that is able to record your consumption every half hour. The first generation followed a standard called SMETS1, and suppliers accessed the data directly, meaning they often stopped working if you switched supplier. The second generation are SMETS2, and suppliers can access the data via DCC, making it easier to switch supplier. Most of the SMETS1 meters will be adopted by the DCC over the next 12 months, allowing their data to be read by other suppliers.
Tracker is a tariff that was created before Agile, that has a different price for gas or electricity each day based on varying wholesale prices.
URL - Uniform Resource Locator, or the address of the webpage. For example, the URL of this page is http://guylipman.com/octopus/api_guide.html.