VHPready (short for Virtual Heat and Power Ready) is an open industrial standard for the steering of decentralized power generators, consumers and energy storage units through a central point. The use of unified standards in the form of certified plants could simplify and accelerate the process of aggregating and connecting these plants to a “virtual power plant”.
Contents
The VHPready standard was originally developed by the electric power company Vattenfall based on international communication standards and was initially utilized for connecting Vattenfalls own plants. In the beginning of 2014 the standard was handed over to the industry alliance VHPready e.V., which is a joint working alliance of industrial partners spearheaded by the Fraunhofer Institute for Open Communication Systems (FOKUS). The “Industrieforum VHPready e.V.” took over all development and propagation efforts of the standard.
Background
In recent times, decentralized power generation units such as wind turbines, solar power plants, biogas plants, small hydro plants, mini/micro CHP plants, steerable consumers and energy storages have gained considerable influence. One approach to integrate them in the power supply and to exploit synergies between them consists in the interconnection of these decentralized systems into virtual power plants. This can help to intelligently harmonize the production and consumption of electric energy, which should allow a better integration of renewable energies and decentralized power systems, a reduction in the maximum load of the electricity transmission system and cost advantages for market participants. An intelligent electricity grid plays an important role in this (see Smart Grid). As an incentive for the provision of so-called flexibility, different pricing mechanisms can be applied. Some of them, such as ancillary services (see Operating reserve), are already in use today.
So far, the connection of the plants is carried out relying on manufacturer-specific information and communication standards while using different data models. An open industrial standard can help facilitate and accelerate the connection and prequalification process for decentralized power plants.
History
The VHPready standard was established by the energy company Vattenfall in the year 2011. Vattenfall published version 3.0 of the VHPready specification in October 2012. Due to the large interest in the specification, it was decided to turn the VHPready standard into a generally applicable and open industrial standard. For this reason, the neutral and cross-industry alliance VHPready e.V. was founded in 2014, which has taken over the development of the standard and the certification process of VHPready-compliant system components. Vattenfall has transferred all rights and work results to the industry alliance VHPready e.V., in which it operates as an equal member.
Following the release of the White Paper for VHPready 4.0 to the public in February 2015, the specification was published in September 2015. In addition, the internal service company VHPready Services GmbH was founded in March 2015, which henceforth is responsible for the whole certification process.
Scope and certification
The VHPready standard encompasses different requirements regarding the system configuration and necessary steering and measuring equipment. Supported plant types range from power generation units to power consuming units to power storage units.
The certification process is carried out by VHPready Services GmbH and approved testing laboratories. After receiving an application for the VHPready certificate, VHPready Services GmbH will instruct testing laboratories to test the plants on the basis of the VHPready-technical requirements. The process is divided in two parts: the first part consists of static conformance tests, where the systems and their properties are checked against the specifications provided by the VHPready standard, followed by verification of the dynamic properties of the system, meaning tests under controlled conditions.
In the second part end-to-end tests are done with the aid of reference systems. After successful testing and approval of the testing report by VHPready Services GmbH the plants will receive a product-related VHPready certificate. If the product offered by a plant is changed, then the prequalification process needs to be redone.
Technical details
In order to obtain the VHPready certificate, the plants must meet certain minimum requirements, which ensure a smooth connection to a virtual power plant. The requirements consider the connection protocols used, the technical performance requirements, security of data transmission and types of commands to the plants, and other topics. The focus lies on the data communication, remote monitoring and remote control of the plants.
As a basis for the communication serves the TCP / IP-based and signal-oriented transmission protocol IEC 60870-5-104 or a TCP / IP-based, object-oriented approach compliant with IEC 61850-7-420.
The latest version of the specification is VHPready 4.0. The core element of it is an extensive data point list which helps integrate different energy systems into virtual power plants using the telecontrol protocols IEC 60870-5-104 or IEC 61850-7-420. In addition to a plant park with a set of different energy systems, this data point list facilitates the integration of combined heat and power units (CHPs), wind and solar plants, heat pumps, batteries, electric heating, boilers and buffer tanks. Data points for meters and external signal contacts are also available. The data transmission is secured by establishing a virtual private network (VPN) based on OpenVPN with SSL / TLS (Secure Sockets Layer, Transport Layer Security).
A key objective of VHPready is the establishment of subsets (subsets or profiles) of the norms used, so that during the certification process and project realization only certain profiles have to be used. This way project-specific consultation concerning the details of the utilized norms can be minimized. All tests for the certification of plants in accordance with the VHPready standard follow internationally standardized methods like ISO/IEC and ETSI.
Members of VHPready e.V.
The following companies are members of the industry alliance VHPready e.V. (Status as of January 2016):